This site is supported by donations to The OEIS Foundation.

# Index to OEIS: Section Se

# Index to OEIS: Section Se

- This is a section of the Index to the
**OEIS®**. - For further information see the main
**Index to OEIS**page. - Please read Index: Instructions For Updating Index to OEIS before making changes to this page.
- If you did not find what you were looking for in this Index, you can always search the database for a particular word or phrase.
- Full list of sections:

[ Aa | Ab | Al | Am | Ap | Ar | Ba | Be | Bi | Bl | Bo | Br | Ca | Ce | Ch | Cl | Coa | Coi | Com | Con | Cor | Cu | Cy | Da | De | Di | Do | Ea | Ed | El | Eu | Fa | Fe | Fi | Fo | Fu | Ga | Ge | Go | Gra | Gre | Ha | He | Ho | Ia | In | J | K | La | Lc | Li | Lo | Lu | M | Mag | Map | Mat | Me | Mo | Mu | N | Na | Ne | Ni | No | Nu | O | Pac | Par | Pas | Pea | Per | Ph | Poi | Pol | Pos | Pow | Pra | Pri | Pro | Ps | Qua | Que | Ra | Rea | Rel | Res | Ro | Ru | Sa | Se | Si | Sk | So | Sp | Sq | St | Su | Sw | Ta | Te | Th | To | Tra | Tri | Tu | U | V | Wa | We | Wi | X | Y | Z | 1 | 2 | 3 | 4 ]

sec(x), Taylor series for: A046976*/A046977*, A000364*/A000142*

sec(x): see also A000111

secant numbers: A000364*

secant-tangent numbers: A000111*

Second moment:: A006733, A006741, A006737

Secret Santa: A102262/A102263

segmented numbers: A002048*

- self numbers: see Columbian or self numbers

self-avoiding walks: see walks, self-avoiding

Self-contained numbers:: A005184

- self-describing numbers: Autobiographical numbers: A047841 (A104784 is an erroneous version), self-describing primes: A108810, semiprimes: A173101, not complete information: A059504, primes therein: A109775, self descriptive (possibly redundant) numbers: A109776

** self-dual, sequences related to : **

- self-dual:: A005137, A003179, A007147, A003178, A001532, A002080, A001206, A006688, A002841, A004104, A001531, A003184, A002077, A004107

** self-generating sequences, sequences related to : **

- self-generating sequences:: A005041, A007538, A003160, A003045, A003044, A005243, A001149, A005244, A005242, A001856, A003145, A003144, A003157, A003156, A003146

self-inverse sequences: see also permutations of the integers, self-inverse

##### self-referencing sequences

- general: A141435, A121459, A230086 (a(n+a(n)) is prime).
- referring to its digits: A114134 (a(n)-th digit = 1, increasing), A098645 (idem, no other 1's), A098670 (a(n)-th digit = 2), A210414-A210423 (a(n)-th digit is 0/1/.../9, not growing), A126968 (a(n) starts with a(n)-th digit of the seq.), A126969 (idem, increasing), A129946 (fixed under removal of all a(n)-th digits), A210538 (a(n) divisible by n-th digit of the sequence).
- self-referential sequences: see also Sequences whose definition involves A_n (or An)

semi-Fibonacci numbers: A030067*

- semigroups : A001423*, A023814*, A027851*, A079175
- semigroups, asymmetric: A058104*, A058105, A058106, A058107*, A058113-A058115, A058168-A058170
- semigroups, by idempotents: A002786, A002787, A002788, A005591, A006966, A058108*, A058109-A058122, A058123*, A058166*, A058167-A058170
- semigroups, commutative: A001426*, A006966, A023815*, A058105, A058116, A058117, A058167, A058168, A079201
- semigroups, idempotent: A002788*, A006966, A030449, A030450, A058112*, A058115, A058122
- semigroups, inverse: A001428*
- semigroups, non-commutative: A079198, A079199, A079180
- semigroups, numerical: A007323
- semigroups, regular: A001427
- semigroups, relation: A007903
- semigroups, self-converse: A029851*, A058106, A058118-A058122, A058169
- semigroups, with identity: see monoids
- semigroups: see also monoids
- semigroups: see also A030450, A079207, A079208, A079209, A079241, A079242, A079243, A079244, A079245

semiorders: A006531

semiperfect numbers: A005835*

** semiprimes (or semi-primes): sequences related to : **

- semiprimes (or semi-primes): A001358*, A072000 ("pi"), A064911, A066265
- semiprimes: see also almost primes

separating families: A007600

** sequence and first differences include all numbers, etc.: sequences related to : **

- sequence and first differences include all numbers, etc.: (1) A005228*, A030124, A037257, A037258, A037259, A061577, A140778, A129198, A129199
- sequence and first differences include all numbers, etc.: (2) A100707, A093903, A005132, A006509, A081145, A099004, A225376, A225377, A225378, A225385, A225386, A225387
- sequence and first differences include all numbers, etc.: see also Hofstadter sequences

sequences by number of increases: A000575

** sequences defined by recurrences which may not be infinite: **

sequences depending on A-numbers in OEIS: see diagonal sequences

**Sequences in Classic Books**

Sequences of prescribed quadratic character:: A001990, A001992, A001988, A001986

** sequences offering a monetary reward, sequences related to : **

- sequences offering a monetary reward: A030979, A057641, A079526, A058209, A185636, A216868, A231201, A232174, A247824, A271518, A280356, A280831, A281976, A287616,

** sequences that contain every finite sequence of nonnegative integers, sequences related to : **

- sequences that contain every finite sequence of nonnegative integers: A067255 A108730 A108731 A098280 A098281 A098282 A108244 A108736 A108737 A055932 A066099

##### sequences that need extending :

- sequences that need extending, challenge problems: Looking for a good challenge? Try any of the following:
- sequences that need extending, challenge problems: A000937 (closed n-snake-in-the-box problem)
- sequences that need extending, challenge problems: A003142 (no-3-in-line on 3^n grid)
- sequences that need extending, challenge problems: A004137 (maximal number of edges in a graceful graph on n nodes)
- sequences that need extending, challenge problems: A006945 (smallest odd number that requires n Miller-Rabin primality tests)
- sequences that need extending, challenge problems: A016088 and A046024 (when does Sum 1/p (p prime) exceed n?)
- sequences that need extending, challenge problems: A076523 (maximal number of halving lines for 2n points in plane)
- sequences that need extending, challenge problems: A081287 (packing squares of sizes 1 to n)
- sequences that need extending, challenge problems: A085000 (maximal determinant of an n X n matrix using the integers 1 to n^2)
- sequences that need extending, challenge problems: A087725 (n X n generalization of Sam Loyd's Fifteen Puzzle)
- sequences that need extending, challenge problems: A087983 (values taken by permanent of n X n (0,1)-matrix)
- sequences that need extending, challenge problems: A089472 (values taken by the determinant of a real (0,1)-matrix of order n)
- sequences that need extending, challenge problems: A099155 (snake-in-the-box problem)
- sequences that need extending, challenge problems: {a(1) = 1, a(2) = 4, a(3) <= 8, a(4) <= 24, a(5) <= 32}, from Erich Friedman, not yet in OEIS: minimum value of k so that k copies each of cubes of sides 1 through n can be used to exactly fill some rectangular box
- sequences that need extending, short sequences that badly need extending: (1) A001220 (Wieferich primes), A003142 (non-collinear points in cube), A007540 (Wilson primes), A048872 (line arrangements), A054909 (even unimodular lattice), A055549 (normal matrices), A058759 and A056287 (Shannon switching function), A074025 (triplewhist tournaments)
- sequences that need extending, short sequences that badly need extending: (2) A076337 (Riesel numbers)
- sequences that need extending: see also Challenge Problems: Independent Sets in Graphs
- sequences that need extending: see also conjectured sequences
- sequences that need extending: see also unsolved problems in number theory (selected)
- sequences that need extending: see also huge web page with full list of sequences that need extending

** sequences which agree for a long time but are different : **

- sequences which agree for a long time but are different: (A004953, A004973), (A007698, A007699), (A010918, A019484), (A025646, A025661), (A025647, A025653), (A027641, A227570, A227573, ignoring n=1), (A030299, A352991), (A078608, a(n) = floor(2*n/(log 2)); [cf. A129935]), (A079599, A126002), (A084500, A084557), (A098502, A158953), (A103127, A103192), (A103747, A132417), (A159887, A159888), (A235921, A236432)

** sequences which grow too rapidly to have their own entries : **

- sequences which grow too rapidly to have their own entries, see: Ackermann numbers (comments on A046859), Conway-Guy sequence (comments on A046859), Friedman sequence (comments on A014221), Goodstein's function or the Goodstein sequence (comments on A056041), n!!...! (comments on A000142 and A000197), TREE sequence (see Kruskal's tree theorem on Wikipedia), SSCG sequence (see Friedman’s SSCG function on Wikipedia)
- ((2n)!)!+n!: see Elsholtz, Christian. Golomb’s Conjecture on Prime Gaps. The American Mathematical Monthly 124.4 (2017): 365-368.

#### sequences whose definition involves A_n (or An):

- n-th term of A_n: A051070, A091967
- (n-th term of A_n) + 1: A107357, A102288
- n such that n is not in A_n: A053169, A053873
- initial term of A_n: A031214
- sum of first n terms of A_n: A039928, A100543
- See also: A111157, A111198, A250219, A358291

sequences whose extension requires factoring large numbers: A031439, A031440, A031442, A082021, A082132, A034970, A084599, A191648

- sequences with a gap (some later term is known) (1): A000043, A001438, A002853, A005136, A006066, A016729, A027623, A037289, A048893,
- sequences with a gap (some later term is known) (2): A051070, A063984, A064156, A068314, A068489, A070911, A072127, A072128,
- sequences with a gap (some later term is known) (3): A072288, A074025, A077659, A078457, A078714, A078814, A080371, A080372,
- sequences with a gap (some later term is known) (4): A080802, A088622, A091295, A091967, A094670, A098472, A098876, A100804,
- sequences with a gap (some later term is known) (5): A103833, A105674, A105676, A105677, A109886, A110409, A112822, A113571,
- sequences with a gap (some later term is known) (6): A114457, A118710, A119479, A119734, A121154
- sequences with a gap (some later term is known) (7): A002982, A005849, A055233, A064593, A066289
- sequences with a gap (some later term is known) (8): (circulant graphs) A049287, A049288, A049289, A049297, A049309, A060966, A082276

sequences with a large but finite number of terms: see finite sequences with a large number of terms

Serbian: A056597

Serbian: see also Index entries for sequences related to number of letters in n

** series-parallel , sequences related to "series-parallel" : **

- series-parallel networks, approximation to: A058585
- series-parallel networks: A000084* A000669* A001572 A001573 A001574 A001575 A001677 A006349 A006350 A006351
- series-parallel networks: see also Moon (1987), "Some enumerative results on series-parallel networks", sequences mentioned in
- series-parallel numbers: A000137 A000163 A000432 A000527 A005840 A007803 A036654 A036655 A048172 A051045 A051389 A053554

**set partitions**

- set partitions: A000110, A193023
- set partitions: see also Bell numbers
- set partitions: see also Stirling numbers of 2nd kind
- set partitions: see also under partitions

sets of lists: A000262, A002868

sets: see also under partitions

sexy prime pairs: A023201, A046117

SHA-256: A365749, A366061

shadow of constants: A108912, A110557, A110621, A110623

Shannon switching function: A058759*

Shell sort: A003462, A033622, A036562, A036564, A036569, A055875, A055876

Shell sort: see also sorting

** shift registers , sequences related to : **

- shift registers, enumeration of output sequences: A000013, A000016, A000031
- shift registers, enumeration of: A001139
- shift registers, periods: A005417
- shift registers, see also necklaces

** shifts left when transformed, sequences related to : **

- shifts left when transformed:: (1) A007461, A007439, A007560, A007464, A003238, A007562, A007477, A007558, A007462, A007463, A007548, A007469
- shifts left when transformed:: (2) A003659, A007460, A007551, A007557, A007561, A007563, A007472, A007549, A007470, A007564, A007556

shoe lacing: see lacing a shoe

shoelaces: see lacing a shoe

shogi (Japanese chess): A062103

short sequences that need extending, see sequences that need extending

** shuffle , shuffling etc., sequences related to : **

- shuffle groups: see groups, shuffle
- shuffling (1): A000375 A000376 A002139 A007070 A007071 A007346 A014525 A014766 A014767 A019567
- shuffling (2): A024222 A024542 A035485 A035490 A035491 A035492 A035493 A035494 A035499 A035500 A035501 A047992
- shuffling (3): A002326* A055388 A051732* A051733 A217948

- This is a section of the Index to the
**OEIS®**. - For further information see the main
**Index to OEIS**page. - Please read Index: Instructions For Updating Index to OEIS before making changes to this page.
- If you did not find what you were looking for in this Index, you can always search the database for a particular word or phrase.
- Full list of sections:

[ Aa | Ab | Al | Am | Ap | Ar | Ba | Be | Bi | Bl | Bo | Br | Ca | Ce | Ch | Cl | Coa | Coi | Com | Con | Cor | Cu | Cy | Da | De | Di | Do | Ea | Ed | El | Eu | Fa | Fe | Fi | Fo | Fu | Ga | Ge | Go | Gra | Gre | Ha | He | Ho | Ia | In | J | K | La | Lc | Li | Lo | Lu | M | Mag | Map | Mat | Me | Mo | Mu | N | Na | Ne | Ni | No | Nu | O | Pac | Par | Pas | Pea | Per | Ph | Poi | Pol | Pos | Pow | Pra | Pri | Pro | Ps | Qua | Que | Ra | Rea | Rel | Res | Ro | Ru | Sa | Se | Si | Sk | So | Sp | Sq | St | Su | Sw | Ta | Te | Th | To | Tra | Tri | Tu | U | V | Wa | We | Wi | X | Y | Z | 1 | 2 | 3 | 4 ]