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 A358956 #5 Dec 08 2022 07:34:47
%S A358956 1,6,78,1196,20280,366288,6908744,134492752,2681961056,54504790720,
%T A358956 1124768357872,23505633975616,496452504891320,10580216111991080,
%U A358956 227237269499825185,4913552644294206262,106877300690757456293,2336971970184440328572,51339570414117180476064
%N A358956 a(n) = coefficient of x^n in A(x) such that: 0 = Sum_{n=-oo..+oo} x^(6*n) * (x^n - 2*A(x))^(7*n+1).
%C A358956 Related identity: 0 = Sum_{n=-oo..+oo} x^n * (y - x^n)^n, which holds formally for all y.
%F A358956 G.f. A(x) = Sum_{n>=0} a(n)*x^n satisfies:
%F A358956 (1) 0 = Sum_{n=-oo..+oo} x^(6*n) * (x^n - 2*A(x))^(7*n+1).
%F A358956 (2) 0 = Sum_{n=-oo..+oo} x^(7*n*(n-1)) / (1 - 2*A(x)*x^n)^(7*n-1).
%e A358956 G.f.: A(x) = 1 + 6*x + 78*x^2 + 1196*x^3 + 20280*x^4 + 366288*x^5 + 6908744*x^6 + 134492752*x^7 + 2681961056*x^8 + 54504790720*x^9 + 1124768357872*x^10 + ...
%o A358956 (PARI) {a(n) = my(A=[1]); for(i=1,n, A=concat(A,0);
%o A358956 A[#A] = polcoeff( sum(n=-#A,#A, x^(6*n) * (x^n - 2*Ser(A))^(7*n+1) ), #A-1)/2);A[n+1]}
%o A358956 for(n=0,25,print1(a(n),", "))
%Y A358956 Cf. A355865, A358952, A358953, A358954, A358955, A358957, A358958, A358959.
%K A358956 nonn
%O A358956 0,2
%A A358956 _Paul D. Hanna_, Dec 07 2022