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A258793 a(n) = [x^n] Product_{k=1..n} 1/(x^(2*k)*(1-x^k)^2). 4
1, 4, 55, 896, 16494, 326422, 6812064, 147937628, 3315019979, 76184664934, 1787702723767, 42688437971038, 1034621287862521, 25398832816003228, 630502487733706193, 15805630063826901440, 399669931534045129915, 10184690536676439639278, 261340023300544414822171 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n) ~ c * d^n / n^(5/2), where d = 29.1694173246928561008040480794933198469510496062455151175744673506960... = r^4/(r-1)^2, where r is the root of the equation polylog(2, 1-r) + log(r)^2 = 0, c = 2.0036140319464... .
MATHEMATICA
Table[SeriesCoefficient[1/Product[x^(2*k)*(1-x^k)^2, {k, 1, n}], {x, 0, n}], {n, 0, 20}]
Table[SeriesCoefficient[1/Product[1-x^k, {k, 1, n}]^2, {x, 0, n*(n+2)}], {n, 0, 20}]
CROSSREFS
Sequence in context: A285366 A202163 A073352 * A195634 A322627 A206384
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Jun 10 2015
STATUS
approved

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Last modified April 23 15:20 EDT 2024. Contains 371916 sequences. (Running on oeis4.)