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 A284319 #11 Mar 25 2017 06:17:22
%S A284319 1,0,-1,0,0,0,0,-1,0,1,0,0,-1,0,1,0,0,-1,0,2,0,-1,-1,0,2,0,-1,-1,0,3,
%T A284319 0,-2,-1,0,3,0,-3,-1,1,4,0,-4,-1,1,4,0,-5,-1,2,5,0,-7,-1,3,5,0,-8,-1,
%U A284319 5,6,-1,-10,-1,6,6,-1,-12,-1,9,7,-2,-14,-1,11,7,-3
%N A284319 Expansion of Product_{k>=0} (1 - x^(5*k+2)) in powers of x.
%F A284319 a(n) = -(1/n)*Sum_{k=1..n} A284280(k)*a(n-k), a(0) = 1.
%t A284319 CoefficientList[Series[Product[1 - x^(5k + 2), {k, 0, 100}], {x, 0, 100}], x] (* _Indranil Ghosh_, Mar 25 2017 *)
%o A284319 (PARI) Vec(prod(k=0, 100, 1 - x^(5*k + 2)) + O(x^101)) \\ _Indranil Ghosh_, Mar 25 2017
%Y A284319 Cf. Product_{k>=0} (1 - x^(5*k+m)): A284314 (m=1), this sequence (m=2), A284320 (m=3), A284317 (m=4).
%Y A284319 Cf. A281272, A284280.
%K A284319 sign
%O A284319 0,20
%A A284319 _Seiichi Manyama_, Mar 25 2017