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 A249928 #6 Feb 07 2025 14:38:02 %S A249928 1,1,4,42,530,7489,113289,1794784,29397876,493818165,8460325159, %T A249928 147264321834,2596986868762,46299572773077,833111268412360, %U A249928 15110637698827976,275970530427257207,5070759797283817869,93671715612197557390,1738657226550598494420,32409645286487921390715 %N A249928 G.f. A(x) satisfies: 1+x = A(x)^2 + A(x)^5 - A(x)^6. %F A249928 G.f.: 1 + Series_Reversion(x - 4*x^2 - 10*x^3 - 10*x^4 - 5*x^5 - x^6). %e A249928 G.f.: A(x) = 1 + x + 4*x^2 + 42*x^3 + 530*x^4 + 7489*x^5 + 113289*x^6 +... %e A249928 Related expansions. %e A249928 A(x)^2 = 1 + 2*x + 9*x^2 + 92*x^3 + 1160*x^4 + 16374*x^5 +... %e A249928 A(x)^5 = 1 + 5*x + 30*x^2 + 300*x^3 + 3775*x^4 + 53226*x^5 +... %e A249928 A(x)^6 = 1 + 6*x + 39*x^2 + 392*x^3 + 4935*x^4 + 69600*x^5 +... %e A249928 where 1+x = A(x)^2 + A(x)^5 - A(x)^6. %o A249928 (PARI) /* From 1+x = A(x)^2 + A(x)^5 - A(x)^6: */ %o A249928 {a(n)=local(A=[1, 1]); for(i=1, n, A=concat(A, 0); A[#A]=-Vec(Ser(A)^2+Ser(A)^5-Ser(A)^6)[#A]); A[n+1]} %o A249928 for(n=0, 25, print1(a(n) , ", ")) %o A249928 (PARI) /* From Series Reversion: */ %o A249928 {a(n)=local(A=1+serreverse(x - 4*x^2 - 10*x^3 - 10*x^4 - 5*x^5 - x^6 + x^2*O(x^n)));polcoeff(A,n)} %o A249928 for(n=0, 25, print1(a(n) , ", ")) %Y A249928 Cf. A249926, A249927, A249929, A249930, A249931, A249932. %K A249928 nonn %O A249928 0,3 %A A249928 _Paul D. Hanna_, Nov 27 2014