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 A358954 #5 Dec 08 2022 07:34:39
%S A358954 1,4,36,384,4568,57920,768760,10543120,148247390,2125715618,
%T A358954 30965114225,456956616284,6817011617601,102640570550600,
%U A358954 1557716916728198,23804070258610024,365964582592739540,5656501536118793076,87846324474413129008,1370097609728212588634,21451062781643458337802
%N A358954 a(n) = coefficient of x^n in A(x) such that: 0 = Sum_{n=-oo..+oo} x^(4*n) * (x^n - 2*A(x))^(5*n+1).
%C A358954 Related identity: 0 = Sum_{n=-oo..+oo} x^n * (y - x^n)^n, which holds formally for all y.
%F A358954 G.f. A(x) = Sum_{n>=0} a(n)*x^n satisfies:
%F A358954 (1) 0 = Sum_{n=-oo..+oo} x^(4*n) * (x^n - 2*A(x))^(5*n+1).
%F A358954 (2) 0 = Sum_{n=-oo..+oo} x^(5*n*(n-1)) / (1 - 2*A(x)*x^n)^(5*n-1).
%e A358954 G.f.: A(x) = 1 + 4*x + 36*x^2 + 384*x^3 + 4568*x^4 + 57920*x^5 + 768760*x^6 + 10543120*x^7 + 148247390*x^8 + 2125715618*x^9 + 30965114225*x^10 + ...
%o A358954 (PARI) {a(n) = my(A=[1]); for(i=1,n, A=concat(A,0);
%o A358954 A[#A] = polcoeff( sum(n=-#A,#A, x^(4*n) * (x^n - 2*Ser(A))^(5*n+1) ), #A-1)/2);A[n+1]}
%o A358954 for(n=0,25,print1(a(n),", "))
%Y A358954 Cf. A355865, A358952, A358953, A358955, A358956, A358957, A358958, A358959.
%K A358954 nonn
%O A358954 0,2
%A A358954 _Paul D. Hanna_, Dec 07 2022