

A292134


Main diagonal of A292133.


4



1, 1, 2, 21, 220, 2705, 40926, 733537, 15124216, 352606050, 9174382490, 263533561852, 8283376452948, 282795708021411, 10420847619031710, 412243715452039440, 17425722339237083120, 783844576340696848341, 37384875796116662077194
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OFFSET

0,3


LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..386


FORMULA

a(n) = [x^n] Product_{k>=1} 1/(1 + n*x^k).
a(n) ~ (1)^n * n^n * (1  1/n + 2/n^2  3/n^3 + 5/n^4  7/n^5 + 11/n^6  15/n^7 + 22/n^8  30/n^9 + 42/n^10  ...), for coefficients, see A000041.  Vaclav Kotesovec, Aug 21 2018


PROG

(PARI) {a(n) = polcoeff(1/prod(k=1, n, 1+n*x^k+x*O(x^n)), n)}


CROSSREFS

Cf. A124577, A291698.
Sequence in context: A131698 A163068 A109684 * A137287 A155872 A323478
Adjacent sequences: A292131 A292132 A292133 * A292135 A292136 A292137


KEYWORD

sign


AUTHOR

Seiichi Manyama, Sep 09 2017


STATUS

approved



