A132290 - OEIS

%I #2 Mar 30 2012 18:37:04

%S 1,2,6,25,129,771,5172,38280,308987,2695586,25231269,251869681,

%T 2667876382,29856632341,351717286357,4347357161694,56222019376378,

%U 758836553993985,10665452531786380,155785594704483911

%N Main diagonal of triangle A132289: a(n) = A132289(n,n) for n>=0.

%C Equals the binomial transform of A125276.

%F G.f. A(x) satisfies: A( x*(1-x)/(1+x-x^2) )/(1+x-x^2) = 1 + x*A(x).

%o (PARI) {a(n)=local(A=[1]);if(n==0,1,for(i=1,n, A=Vec(Ser(concat(concat(A[ #A],A),A[ #A]))/(1-x)));A[n+1])}

%Y Cf. A132289, A125276.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Aug 18 2007