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A305872 Number of nonseparable rooted maps of genus n with one vertex and one face. 1

%I #16 Jun 14 2018 06:36:09

%S 1,1,17,1259,200589,54766516,22839203295,13532959408258,

%T 10826939105517381,11256605684271733244,14762470788227855508388,

%U 23845795018908512860754771,46527914721396710095597849515,107904469663880176355586920421756,293401777662120053352713701982623322

%N Number of nonseparable rooted maps of genus n with one vertex and one face.

%H Gheorghe Coserea, <a href="/A305872/b305872.txt">Table of n, a(n) for n = 0..200</a>

%H T. R. S. Walsh, A. B. Lehman, <a href="https://dx.doi.org/10.1016/0095-8956(75)90050-7">Counting rooted maps by genus. III: Nonseparable maps</a>, J. Combinatorial Theory Ser. B 18 (1975), 222-259.

%F The g.f. A(x) satisfies A035319(x) = A[x*(A035319(x)^4)], where A035319 is the o.g.f. of A035319.

%p g := 1+x ;

%p for itr from 2 to 14 do

%p g := g+a*x^itr;

%p Ax := add(A035319(i)*x^i,i=0..itr+1) ;

%p x*Ax^4 ;

%p z := subs(x=%,g)-Ax ;

%p z := expand(z) ;

%p z := taylor(z,x=0,itr+1) ;

%p z := convert(z,polynom) ;

%p aa := solve(z,a) ;

%p g := g-a*x^itr+aa*x^itr ;

%p print(g) ;

%p end do:

%o (PARI)

%o seq(N) = {

%o my(s = 1+'x*Ser(vector(N, n, (4*n)!/((2*n+1)!*4^n))));

%o Vec(subst(s, 'x, serreverse('x*s^4)));

%o };

%o seq(14) \\ _Gheorghe Coserea_, Jun 13 2018

%Y Cf. A035319.

%K nonn

%O 0,3

%A _R. J. Mathar_, Jun 12 2018

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Last modified April 23 02:53 EDT 2024. Contains 371906 sequences. (Running on oeis4.)