login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A234588 Lexicographically earliest sequence S with property that a(n) is the a(n)-th absolute first difference of S. 0
1, 2, 4, 5, 9, 14, 8, 10, 18, 27, 17, 6, 11, 15, 29, 44, 19, 36, 54, 35, 21, 42, 23, 46, 25, 50, 28, 55, 83, 112, 31, 62, 33, 66, 37, 72, 108, 71, 39, 78, 41, 82, 124, 45, 89, 134, 88, 48, 96, 51, 101, 152, 53, 106, 160, 105, 57, 114, 59, 118, 61, 122, 184, 64 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A kind of self-describing sequence.

Recamán's sequence A005132 is also self-describing in this sense, but comes lexicographically after this one (and you have to drop the initial "0").

If we want S to be monotonically increasing, we get A063733.

REFERENCES

Eric Angelini, Posting to Sequence Fans Mailing List, Nov 26, 2010

LINKS

Table of n, a(n) for n=1..64.

EXAMPLE

If n = 1 2 3 4 5  6 7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 ...

a(n) = 1 2 4 5 9 14 8 10 18 27 17, 6 11 15 29 44 19 36 54 35 21 42 23 46 25 50 28 55 ...

diff =  1 2 1 4 5  6 2  8  9  10 11 5  4  14 15 25 17 18 19 14 21 19 23 21 25 22

d-rank= 1 2 3 4 5  6 7  8  9  10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

hit:    * *   * *  *    *  *   *  *     *  *  *     *

S is tricky to compute; the rule for a(n+1) is "always use the smallest integer not yet in S and not leading to a contradiction".

'14' is in S and '14' says: "The 14th absolute first difference in S equals 14" -- which is true.

CROSSREFS

Cf. A005132, A063733.

Sequence in context: A068372 A068370 A060167 * A118550 A126697 A162406

Adjacent sequences:  A234585 A234586 A234587 * A234589 A234590 A234591

KEYWORD

nonn

AUTHOR

Eric Angelini, Dec 31 2013

EXTENSIONS

More terms from Jon E. Schoenfield, Jan 11 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 3 18:24 EDT 2022. Contains 357237 sequences. (Running on oeis4.)