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 A147701 #5 Oct 02 2017 02:31:16
%S A147701 1,-1,-2,1,1,0,0,3,1,-3,-1,-1,-4,-1,3,1,4,6,-1,-4,1,-5,-12,1,10,-1,4,
%T A147701 18,1,-14,-2,-7,-22,-2,15,2,14,33,-2,-22,3,-20,-52,3,37,-3,22,71,4,
%U A147701 -51,-4,-29,-90,-4,61,4,50,121,-5,-83,5,-67,-174,6,123,-6,74,231,6,-162,-7,-99,-286,-8,195,8,148,376,-9,-254,11,-191
%N A147701 Expansion of q^(1/4) * eta(q) * eta(q^2) * eta(q^5) * eta(q^20) / (eta(q^4) * eta(q^10)^3) in powers of q.
%F A147701 Euler transform of period 20 sequence [ -1, -2, -1, -1, -2, -2, -1, -1, -1, 0, -1, -1, -1, -2, -2, -1, -1, -2, -1, 0, ...].
%F A147701 G.f. is a period 1 Fourier series which satisfies f(-1 / (80 t)) = 20^(1/2) g(t) where q = exp(2 Pi i t) and g() is g.f. for A144724.
%e A147701 1/q - q^3 - 2*q^7 + q^11 + q^15 + 3*q^27 + q^31 - 3*q^35 - q^39 + ...
%o A147701 (PARI) {a(n) = local(A); if( n<0, 0, A = x * O(x^n); polcoeff( eta(x + A) * eta(x^2 + A) * eta(x^5 + A) * eta(x^20 + A) / (eta(x^4 + A) * eta(x^10 + A)^3), n))}
%K A147701 sign
%O A147701 0,3
%A A147701 _Michael Somos_, Nov 10 2008