A132290 Main diagonal of triangle A132289: a(n) = A132289(n,n) for n>=0.

1, 2, 6, 25, 129, 771, 5172, 38280, 308987, 2695586, 25231269, 251869681, 2667876382, 29856632341, 351717286357, 4347357161694, 56222019376378, 758836553993985, 10665452531786380, 155785594704483911

Offset

0,2

Comments

Equals the binomial transform of A125276.

Links

Table of n, a(n) for n=0..19.

Formula

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

Prog

(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])}

Crossrefs

Cf. A132289, A125276.

Sequence in context: A181594 A030915 A030921 * A030933 A299044 A100325

Adjacent sequences: A132287 A132288 A132289 * A132291 A132292 A132293

Keyword

nonn

Author

Paul D. Hanna, Aug 18 2007

Status

approved