cp's OEIS Frontend

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.

A325219 G.f. A(x) satisfies: Sum_{n>=0} x^n*A(x)^(n^2) = Sum_{n>=0} x^n/(1-n*x)^n.

Original entry on oeis.org

1, 1, 1, 3, 14, 81, 554, 4175, 33894, 292482, 2658803, 25312031, 251337905, 2595476384, 27814372541, 308814996237, 3547597450937, 42121414823717, 516406224737906, 6531681539263289, 85162992707351910, 1143744473741844428, 15809784290241899546, 224756696173450416445, 3283701348287927969258, 49267186208121297961411, 758541179347396245098635, 11976195590135148979244826, 193765334786286246261399910
Offset: 0

Views

Author

Paul D. Hanna, Apr 30 2019

Keywords

Examples

			G.f.: A(x) = 1 + x + x^2 + 3*x^3 + 14*x^4 + 81*x^5 + 554*x^6 + 4175*x^7 + 33894*x^8 + 292482*x^9 + 2658803*x^10 + 25312031*x^11 + 251337905*x^12 + ...
such that the following series are equal
B(x) = 1 + x*A(x) + x^2*A(x)^4 + x^3*A(x)^9 + x^4*A(x)^16 + x^5*A(x)^25 + x^6*A(x)^36 + x^7*A(x)^49 + x^8*A(x)^64 + ...
B(x) = 1 + x/(1-x) + x^2/(1-2*x)^2 + x^3/(1-3*x)^3 + x^4/(1-4*x)^4 + x^5/(1-5*x)^5 + x^6/(1-6*x)^6 + x^7/(1-7*x)^7 + x^8/(1-8*x)^8 + ...
where
B(x) = 1 + x + 2*x^2 + 6*x^3 + 23*x^4 + 104*x^5 + 537*x^6 + 3100*x^7 + 19693*x^8 + 136064*x^9 + 1013345*x^10 + 8076644*x^11 + ... + A080108(n)*x^n + ...
		

Crossrefs

Cf. A080108.

Programs

  • PARI
    {a(n) = my(A=[1]); for(i=1, n, A = concat(A, 0);
    A[#A] = polcoeff( sum(m=0, #A, x^m*( 1/(1-m*x +x*O(x^#A))^m - Ser(A)^(m^2)) ), #A) ); A[n+1]}
    for(n=0, 30, print1(a(n), ", "))