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 A284503 #14 Jan 18 2023 02:23:05
%S A284503 1,0,0,0,0,-1,0,0,0,0,0,0,-1,0,0,0,0,1,0,-1,0,0,0,0,1,0,-1,0,0,0,0,2,
%T A284503 0,-1,0,0,-1,0,2,0,-1,0,0,-1,0,3,0,-1,0,0,-2,0,3,0,-1,0,0,-3,0,4,0,-1,
%U A284503 1,0,-4,0,4,0,-1,1,0,-5,0,5,0,-1,2,0,-7,0,5,0
%N A284503 Expansion of Product_{k>=0} (1 - x^(7*k+5)) in powers of x.
%H A284503 Seiichi Manyama, <a href="/A284503/b284503.txt">Table of n, a(n) for n = 0..10000</a>
%F A284503 a(n) = -(1/n) * Sum_{k=1..n} A284446(k) * a(n-k), a(0) = 1.
%t A284503 CoefficientList[Series[Product[1 - x^(7k + 5), {k, 0, 100}], {x, 0, 100}], x] (* _Indranil Ghosh_, Mar 28 2017 *)
%o A284503 (PARI) Vec(prod(k=0, 100, 1 - x^(7*k + 5)) + O(x^101)) \\ _Indranil Ghosh_, Mar 28 2017
%Y A284503 Cf. Product_{k>=0} (1 - x^(7*k+m)): A284499 (m=1), A284500 (m=2), A284501 (m=3), A284502 (m=4), this sequence (m=5), A284504 (m=6).
%Y A284503 Cf. A281455.
%K A284503 sign,look
%O A284503 0,32
%A A284503 _Seiichi Manyama_, Mar 28 2017