This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A160506 #18 Aug 11 2025 07:00:29
%S A160506 1,5,20,65,190,502,1245,2910,6505,13965,29005,58455,114810,220240,
%T A160506 413775,762635,1381550,2463060,4327445,7500260,12836645,21712470,
%U A160506 36323930,60143320,98620425,160238035,258110955,412367705,653709340,1028658150,1607306688
%N A160506 Coefficients in the expansion of C^4/B^5, in Watson's notation of page 106.
%H A160506 Seiichi Manyama, <a href="/A160506/b160506.txt">Table of n, a(n) for n = 0..1000</a>
%H A160506 Watson, G. N., <a href="https://gdz.sub.uni-goettingen.de/id/PPN243919689_0179">Ramanujans Vermutung ueber Zerfaellungsanzahlen.</a> J. Reine Angew. Math. (Crelle), 179 (1938), 97-128.
%F A160506 See Maple code in A160458 for formula.
%F A160506 a(n) ~ sqrt(7/5) * exp(Pi*sqrt(14*n/5)) / (100*n). - _Vaclav Kotesovec_, Nov 28 2016
%e A160506 x^15+5*x^39+20*x^63+65*x^87+190*x^111+502*x^135+1245*x^159+...
%t A160506 nmax = 50; CoefficientList[Series[Product[(1 - x^(5*k))^4/(1 - x^k)^5, {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Nov 28 2016 *)
%Y A160506 Cf. Product_{n>=1} (1 - x^(5*n))^k/(1 - x^n)^(k + 1): A160461 (k=1), A160462 (k=2), A160463 (k=3), this sequence (k=4), A071734 (k=5), A160460 (k=6), A160521 (k=7), A278555 (k=12), A278556 (k=18), A278557 (k=24), A278558 (k=30).
%K A160506 nonn
%O A160506 0,2
%A A160506 _N. J. A. Sloane_, Nov 13 2009