OFFSET
0,22
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
FORMULA
EXAMPLE
G.f. = 1 - x - x^4 + x^5 - x^6 + x^8 - x^9 + x^10 + x^13 + x^17 - x^18 + x^20 - 3*x^21 + ...
MAPLE
a:=series(1/(1+x*mul(1+x^k, k=1..100)), x=0, 76): seq(coeff(a, x, n), n=0..75); # Paolo P. Lava, Apr 02 2019
MATHEMATICA
nmax = 75; CoefficientList[Series[1/(1 + x Product[(1 + x^k), {k, 1, nmax}]), {x, 0, nmax}], x]
a[0] = 1; a[n_] := a[n] = -Sum[PartitionsQ[k - 1] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 75}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Aug 29 2018
STATUS
approved