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 A080964 #13 Jul 02 2018 16:35:56 %S A080964 1,2,0,0,4,4,0,0,2,-2,0,0,-8,-4,0,0,-4,0,0,0,8,-8,0,0,-8,-2,0,0,-16,4, %T A080964 0,0,6,-8,0,0,12,4,0,0,8,8,0,0,-8,4,0,0,-8,2,0,0,24,-4,0,0,0,8,0,0, %U A080964 -16,4,0,0,12,8,0,0,16,0,0,0,10,-8,0,0,-24,0,0,0,-8,-6,0,0,16,8,0,0,-24,-8,0,0,-16,-8,0,0,8,0,0 %N A080964 Euler transform of period-16 sequence [2,-3,2,1,2,-3,2,-6,2,-3,2,1,2,-3,2,-3,...]. %H A080964 Alois P. Heinz, <a href="/A080964/b080964.txt">Table of n, a(n) for n = 0..20000</a> (1501 terms from G. C. Greubel) %F A080964 a(4*n+2) = a(4*n+3) = 0. %F A080964 a(n) = 2*A072071(n) - A072070(n). %F A080964 a(4*n) = A080965(n). %F A080964 a(4*n+1) = 2*A080966(n). %F A080964 Expansion of eta(q^2)^5*eta(q^8)^7/(eta(q)^2*eta(q^4)^4*eta(q^16)^3) in powers of q. - _G. C. Greubel_, Jul 02 2018 %t A080964 eta[q_] := q^(1/24)*QPochhammer[q]; a:= CoefficientList[Series[eta[q^2]^5 *eta[q^8]^7/(eta[q]^2*eta[q^4]^4*eta[q^16]^3), {q, 0, 60}], q]; Table[a[[n]], {n, 1, 70}] (* _G. C. Greubel_, Jul 02 2018 *) %o A080964 (PARI) a(n)=local(X); if(n<0,0,X=x+x*O(x^n); polcoeff(eta(X)^-2*eta(X^2)^5*eta(X^4)^-4*eta(X^8)^7*eta(X^16)^-3,n)) %K A080964 sign %O A080964 0,2 %A A080964 _Michael Somos_, Feb 28 2003