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”).

A059160
Number of ordered ways of writing n as a sum of 5 generalized pentagonal numbers (A001318).
1
1, 5, 15, 30, 45, 56, 65, 85, 115, 150, 171, 175, 185, 205, 260, 300, 325, 340, 350, 415, 440, 485, 500, 505, 580, 581, 650, 645, 675, 815, 815, 910, 845, 865, 985, 951, 1130, 1030, 1060, 1155, 1150, 1370, 1265, 1410, 1495, 1420, 1545, 1460, 1600, 1675, 1690
OFFSET
0,2
LINKS
FORMULA
G.f.: f(x, x^2)^5 where f(,) is Ramanujan's two-variable theta function. - Michael Somos, Jun 08 2012
MATHEMATICA
a[n_] := SeriesCoefficient[(QPochhammer[-q, q^3]* QPochhammer[-q^2, q^3]*QPochhammer[q^3, q^3])^5, {q, 0, n}]; Table[a[n], {n, 0, 50}] (* G. C. Greubel, Jun 12 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Judson Neer, Feb 14 2001
STATUS
approved