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 A160534 #14 Aug 11 2025 07:13:59
%S A160534 1,-7,14,7,-49,21,35,42,-56,-119,105,-70,147,147,-133,-168,-231,252,
%T A160534 -154,315,441,7,-644,-574,595,-679,735,574,196,-406,-840,840,-1470,
%U A160534 854,1260,21,-1617,-966,1575,-1176,1785,1470,35,-1974,-2058,1533,-1988,1932,2387,-301,-2170,-2016,3087,-2422
%N A160534 Coefficients in the expansion of B^7/C, in Watson's notation of page 118.
%H A160534 Seiichi Manyama, <a href="/A160534/b160534.txt">Table of n, a(n) for n = 0..1000</a>
%H A160534 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 A160534 See Maple code in A160525 for formula.
%F A160534 Euler transform of period 7 sequence [ -7, -7, -7, -7, -7, -7, -6, ...]. - _Alois P. Heinz_, Jan 07 2017
%e A160534 1-7*x^24+14*x^48+7*x^72-49*x^96+21*x^120+35*x^144+42*x^168-...
%p A160534 with(numtheory):
%p A160534 a:= proc(n) option remember; `if`(n=0, 1, add(add(d*
%p A160534 `if`(irem(d, 7)=0, -6, -7), d=divisors(j))*a(n-j), j=1..n)/n)
%p A160534 end:
%p A160534 seq(a(n), n=0..70); # _Alois P. Heinz_, Jan 07 2017
%t A160534 a[n_] := a[n] = If[n==0, 1, Sum[DivisorSum[j, #*If[Mod[#, 7]==0, -6, -7]&]* a[n-j], {j, 1, n}]/n]; Table[a[n], {n, 0, 70}] (* _Jean-François Alcover_, Mar 13 2017, after _Alois P. Heinz_ *)
%K A160534 sign
%O A160534 0,2
%A A160534 _N. J. A. Sloane_, Nov 14 2009