login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A022591
Expansion of Product_{m>=1} (1+q^m)^27.
2
1, 27, 378, 3681, 28134, 180144, 1005957, 5032422, 22986801, 97229361, 384953553, 1438738443, 5110502256, 17348445108, 56541857409, 177611637141, 539501563962, 1589134470966, 4550281700055, 12692702415312, 34556103662778, 91975719684573, 239686155975618
OFFSET
0,2
LINKS
FORMULA
a(n) ~ sqrt(3) * exp(3 * Pi * sqrt(n)) / (32768 * n^(3/4)). - Vaclav Kotesovec, Mar 05 2015
MATHEMATICA
nmax=50; CoefficientList[Series[Product[(1+q^m)^27, {m, 1, nmax}], {q, 0, nmax}], q] (* Vaclav Kotesovec, Mar 05 2015 *)
PROG
(PARI) m=50; q='q+O('q^m); Vec(prod(n=1, m, (1+q^n)^27)) \\ G. C. Greubel, Feb 19 2018
(Magma) Coefficients(&*[(1+x^m)^27:m in [1..40]])[1..40] where x is PolynomialRing(Integers()).1; // G. C. Greubel, Feb 19 2018
CROSSREFS
Column k=27 of A286335.
Sequence in context: A341564 A162726 A010979 * A321954 A000535 A251770
KEYWORD
nonn
STATUS
approved