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 A283169 #16 Mar 04 2017 13:48:52
%S A283169 1,-13,65,-126,-117,988,-1377,-1157,5382,-4419,-4212,12519,-11179,
%T A283169 -5058,27378,-23005,-16488,44343,-30249,-18513,73710,-56259,-38741,
%U A283169 93483,-69570,-23778,137266,-90396,-74079,140292,-108621,-39249,222624,-145710,-99234
%N A283169 Expansion of exp( Sum_{n>=1} -sigma(9*n)*x^n/n ) in powers of x.
%H A283169 Seiichi Manyama, <a href="/A283169/b283169.txt">Table of n, a(n) for n = 0..1000</a>
%F A283169 G.f.: Product_{n>=1} (1 - x^n)^13/(1 - x^(3*n))^4.
%F A283169 a(n) = -(1/n)*Sum_{k=1..n} sigma(9*k)*a(n-k). - _Seiichi Manyama_, Mar 04 2017
%Y A283169 Cf. A283121 (exp( Sum_{n>=1} sigma(9*n)*x^n/n )), A283123 (sigma(9*n)).
%Y A283169 Cf. exp( Sum_{n>=1} -sigma(k*n)*x^n/n ): A115110 (k=2), A185654 (k=3), A283163 (k=4), A282937 (k=5), A283164 (k=6), A282942 (k=7), A283168 (k=8), this sequence (k=9).
%K A283169 sign
%O A283169 0,2
%A A283169 _Seiichi Manyama_, Mar 02 2017