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 A303926 #11 Sep 29 2023 10:29:21 %S A303926 1,1,2,12,130,1912,34715,743217,18255118,505070221,15532353184, %T A303926 525533183871,19403298048040,776437898905606,33479679336072541, %U A303926 1547841068340501230,76390272348430998076,4008960603544297652028,222949077434693015546579,13098226217965693342007714,810657425687536689904281842 %N A303926 G.f. A(x) satisfies: 1 = Sum_{n>=0} ( (1 + x*A(x))^n - A(x) )^n. %C A303926 Compare to: 1 = Sum_{n>=0} ( (1 + x*G(x))^k - G(x) )^n holds trivially for fixed k>0 when G(x) = (1 + x*G(x))^k ; this sequence explores the case when k varies with n. %F A303926 G.f. A(x) satisfies: %F A303926 (1) 1 = Sum_{n>=0} ( (1 + x*A(x))^n - A(x) )^n. %F A303926 (2) 1 = Sum_{n>=0} (1 + x*A(x))^(n^2) / (1 + A(x)*(1 + x*A(x))^n)^(n+1). - _Paul D. Hanna_, Dec 06 2018 %F A303926 G.f.: x/Series_Reversion( x*F(x) ) such that 1 = Sum_{n>=0} ((1 + x*F(x)^2)^n - F(x))^n, where F(x) is the g.f. of A303927. %F A303926 G.f.: sqrt( x/Series_Reversion( x*G(x)^2 ) ) such that 1 = Sum_{n>=0} ((1 + x*G(x)^3)^n - G(x))^n, where G(x) is the g.f. of A303928. %e A303926 G.f.: A(x) = 1 + x + 2*x^2 + 12*x^3 + 130*x^4 + 1912*x^5 + 34715*x^6 + 743217*x^7 + 18255118*x^8 + 505070221*x^9 + 15532353184*x^10 + ... %e A303926 such that %e A303926 1 = 1 + ((1 + x*A(x)) - A(x)) + ((1 + x*A(x))^2 - A(x))^2 + ((1 + x*A(x))^3 - A(x))^3 + ((1 + x*A(x))^4 - A(x))^4 + ((1 + x*A(x))^5 - A(x))^5 + ... %o A303926 (PARI) {a(n) = my(A=[1]); for(i=0,n, A=concat(A,0); A[#A] = Vec( sum(m=0,#A, ( (1 + x*Ser(A))^m - Ser(A))^m ) )[#A] ); A[n+1]} %o A303926 for(n=0,30, print1(a(n),", ")) %Y A303926 Cf. A303927, A303928, A303923, A303056. %K A303926 nonn %O A303926 0,3 %A A303926 _Paul D. Hanna_, May 03 2018