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 A361302 #10 Mar 18 2023 03:39:26 %S A361302 1,1,12,291,10243,460632,24830853,1546531419,108716955930, %T A361302 8489321379453,727903248520260,67935651633100242,6853940772480079902, %U A361302 743261410711529857459,86224073603509482578211,10656471864208782754351131,1398062659621217619155428209 %N A361302 G.f. A(x) satisfies A(x) = Series_Reversion(x - x^3*A'(x)^3). %H A361302 Paul D. Hanna, <a href="/A361302/b361302.txt">Table of n, a(n) for n = 1..300</a> %F A361302 G.f. A(x) = Sum_{n>=1} a(n)*x^(2*n-1) may be defined by the following. %F A361302 (1) A(x) = Series_Reversion(x - x^3*A'(x)^3). %F A361302 (2) A(x) = x + A(x)^3 * A'(A(x))^3. %F A361302 (3) A(x) = x * exp( Sum_{n>=1} d^(n-1)/dx^(n-1) x^(3*n-1) * A'(x)^(3*n) / n! ). %F A361302 (4) A'(x) = Sum_{n>=0} d^n/dx^n x^(3*n) * A'(x)^(3*n) / n! is the g.f. of A361536. %F A361302 (5) a(n) = A361536(n-1)/(2*n-1) for n >= 1. %e A361302 G.f.: A(x) = x + x^3 + 12*x^5 + 291*x^7 + 10243*x^9 + 460632*x^11 + 24830853*x^13 + 1546531419*x^15 + 108716955930*x^17 + ... + a(n)*x^(2*n-1) + ... %e A361302 By definition, A(x - x^3*A'(x)^3) = x, where %e A361302 A'(x) = 1 + 3*x^2 + 60*x^4 + 2037*x^6 + 92187*x^8 + 5066952*x^10 + 322801089*x^12 + 23197971285*x^14 + ... + A361536(n)*x^(2*n) + ... %e A361302 Also, %e A361302 A'(x) = 1 + (d/dx x^3*A'(x)^3) + (d^2/dx^2 x^6*A'(x)^6)/2! + (d^3/dx^3 x^9*A'(x)^9)/3! + (d^4/dx^4 x^12*A'(x)^12)/4! + (d^5/dx^5 x^15*A'(x)^15)/5! + ... + (d^n/dx^n x^(3*n)*A'(x)^(3*n))/n! + ... %e A361302 Further, %e A361302 A(x) = x * exp( x^2*A'(x)^3 + (d/dx x^5*A'(x)^6)/2! + (d^2/dx^2 x^8*A'(x)^9)/3! + (d^3/dx^3 x^11*A'(x)^12)/4! + (d^4/dx^4 x^14*A'(x)^15)/5! + ... + (d^(n-1)/dx^(n-1) x^(3*n-1)*A'(x)^(3*n))/n! + ... ). %o A361302 (PARI) {a(n) = my(A=x+x^3); for(i=1, n, A = serreverse(x - x^3*A'^3 +x*O(x^(2*n)))); polcoeff(A, 2*n-1)} %o A361302 for(n=1, 25, print1(a(n), ", ")) %Y A361302 Cf. A361536. %Y A361302 Cf. A229619, A360976, A360977, A360978, A361307, A361308, A361309, A361310, A361311. %K A361302 nonn %O A361302 1,3 %A A361302 _Paul D. Hanna_, Mar 17 2023