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 A329957 #3 Nov 29 2019 13:35:24
%S A329957 1,-4,5,-2,2,-6,8,-4,2,-12,13,-4,4,-6,10,-4,5,-20,10,-2,6,-12,18,-4,6,
%T A329957 -24,16,-6,4,-6,20,-8,7,-20,10,-10,4,-18,24,-4,6,-24,29,-6,8,-18,20,
%U A329957 -8,4,-28,20,-8,10,-12,18,-8,8,-36,26,-6,12,-12,20,-8,8,-44
%N A329957 Expansion of q^(-2/3) * eta(q)^4 * eta(q^6)^4 / (eta(q^2)^3 * eta(q^3)^2) in powers of q.
%F A329957 Euler transform of period 6 sequence [-4, -1, -2, -1, -4, -3, ...].
%F A329957 G.f.: Product_{k>=1} (1 - x^k)^4 * (1 - x^(6*k))^4 / ((1 - x^(2*k))^3 * (1 - x^(3*k))^2).
%F A329957 A329955(3*n + 2) = -2 * a(n).
%e A329957 G.f. = 1 - 4*x + 5*x^2 - 2*x^3 + 2*x^4 - 6*x^5 + 8*x^6 - 4*x^7 + ...
%e A329957 G.f. = q^2 - 4*q^5 + 5*q^8 - 2*q^11 + 2*q^14 - 6*q^17 + 8*q^20 + ...
%t A329957 a[ n_] := SeriesCoefficient[ QPochhammer[ x]^4 QPochhammer[ x^6]^5 / (QPochhammer[ x^2]^3 QPochhammer[ x^3]^2), {x, 0, n}];
%o A329957 (PARI) {a(n) = my(A); if( n<0, 0, A = x * O(x^n); polcoeff( eta(x + A)^4 * eta(x^6 + A)^4 / (eta(x^2 + A)^3 * eta(x^3 + A)^2), n))};
%Y A329957 Cf. A329955.
%K A329957 sign
%O A329957 0,2
%A A329957 _Michael Somos_, Nov 29 2019