A300702 Number of compositions (ordered partitions) of n into parts that do not divide n.
1, 0, 0, 0, 0, 2, 0, 7, 2, 7, 7, 54, 2, 143, 33, 47, 30, 986, 23, 2583, 58, 1018, 828, 17710, 32, 23866, 3917, 14586, 1368, 317810, 248, 832039, 5902, 188953, 85038, 1505979, 602, 14930351, 393663, 2350986, 13524, 102334154, 16401, 267914295, 431711, 4438212, 8400611, 1836311902
Offset: 0
Keywords
Examples
a(7) = 7 because we have [5, 2], [4, 3], [3, 4], [3, 2, 2], [2, 5], [2, 3, 2] and [2, 2, 3].
Links
Programs
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Maple
a:= proc(m) option remember; local b; b:= proc(n) option remember; `if`(n=0, 1, add(`if`( irem(m, j)=0, 0, b(n-j)), j=2..n)) end; b(m) end: seq(a(n), n=0..60); # Alois P. Heinz, Mar 11 2018
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Mathematica
Table[SeriesCoefficient[1/(1 - Sum[Boole[Mod[n, k] != 0] x^k, {k, 1, n}]), {x, 0, n}], {n, 0, 47}]