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 A249932 #7 Feb 07 2025 14:40:42
%S A249932 1,1,9,189,4893,141771,4399549,143008579,4806584226,165685071354,
%T A249932 5825261477574,208089042731934,7531002619598458,275548081670765638,
%U A249932 10175724606458649366,378783118623851279250,14197727780171976218883,535401733845392629890255,20298674469757725391376887
%N A249932 G.f. A(x) satisfies: 1+x = 2*A(x)^4 - A(x)^7.
%F A249932 G.f.: 1 + Series_Reversion(x - 9*x^2 - 27*x^3 - 33*x^4 - 21*x^5 - 7*x^6 - x^7).
%e A249932 G.f.: A(x) = 1 + x + 9*x^2 + 189*x^3 + 4893*x^4 + 141771*x^5 +...
%e A249932 Related expansions.
%e A249932 A(x)^4 = 1 + 4*x + 42*x^2 + 868*x^3 + 22435*x^4 + 649488*x^5 +...
%e A249932 A(x)^7 = 1 + 7*x + 84*x^2 + 1736*x^3 + 44870*x^4 + 1298976*x^5 +...
%e A249932 where 1+x = 2*A(x)^4 - A(x)^7.
%o A249932 (PARI) /* From 1+x = 2*A(x)^4 - A(x)^7: */
%o A249932 {a(n)=local(A=[1, 1]); for(i=1, n, A=concat(A, 0); A[#A]=-Vec(2*Ser(A)^4-Ser(A)^7)[#A]); A[n+1]}
%o A249932 for(n=0, 25, print1(a(n) , ", "))
%o A249932 (PARI) /* From Series Reversion: */
%o A249932 {a(n)=local(A=1+serreverse(x - 9*x^2 - 27*x^3 - 33*x^4 - 21*x^5 - 7*x^6 - x^7 + x^2*O(x^n)));polcoeff(A,n)}
%o A249932 for(n=0, 25, print1(a(n) , ", "))
%Y A249932 Cf. A249926, A249927, A249928, A249929, A249930, A249931.
%K A249932 nonn
%O A249932 0,3
%A A249932 _Paul D. Hanna_, Nov 27 2014