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A337451 Number of relatively prime strict compositions of n with no 1's. 11
0, 0, 0, 0, 0, 2, 0, 4, 2, 10, 8, 20, 14, 34, 52, 72, 90, 146, 172, 244, 390, 502, 680, 956, 1218, 1686, 2104, 3436, 4078, 5786, 7200, 10108, 12626, 17346, 20876, 32836, 38686, 53674, 67144, 91528, 113426, 152810, 189124, 245884, 343350, 428494, 552548, 719156 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

A strict composition of n is a finite sequence of distinct positive integers summing to n.

LINKS

Fausto A. C. Cariboni, Table of n, a(n) for n = 0..350

EXAMPLE

The a(5) = 2 through a(10) = 8 compositions (empty column indicated by dot):

  (2,3)  .  (2,5)  (3,5)  (2,7)    (3,7)

  (3,2)     (3,4)  (5,3)  (4,5)    (7,3)

            (4,3)         (5,4)    (2,3,5)

            (5,2)         (7,2)    (2,5,3)

                          (2,3,4)  (3,2,5)

                          (2,4,3)  (3,5,2)

                          (3,2,4)  (5,2,3)

                          (3,4,2)  (5,3,2)

                          (4,2,3)

                          (4,3,2)

MATHEMATICA

Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], UnsameQ@@#&&!MemberQ[#, 1]&&GCD@@#==1&]], {n, 0, 15}]

CROSSREFS

A032022 does not require relative primality.

A302698 is the unordered non-strict version.

A332004 is the version allowing 1's.

A337450 is the non-strict version.

A337452 is the unordered version.

A000837 counts relatively prime partitions.

A032020 counts strict compositions.

A078374 counts strict relatively prime partitions.

A002865 counts partitions with no 1's.

A212804 counts compositions with no 1's.

A291166 appears to rank relatively prime compositions.

A337462 counts pairwise coprime compositions.

A337561 counts strict pairwise coprime compositions.

Cf. A000010, A007359, A101268, A178472, A216652, A289509, A337562, A337563.

Sequence in context: A234312 A244136 A338212 * A133168 A145382 A192423

Adjacent sequences:  A337448 A337449 A337450 * A337452 A337453 A337454

KEYWORD

nonn

AUTHOR

Gus Wiseman, Aug 31 2020

STATUS

approved

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Last modified March 7 12:19 EST 2021. Contains 341885 sequences. (Running on oeis4.)