A117505 - OEIS

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A117505

Triangle of coefficients for polynomials used for the column g.f.s of triangle A116880, called CM(1,2).

1, 2, 1, 2, 4, 3, 2, 4, 16, 13, 2, 4, 16, 80, 67, 2, 4, 16, 80, 448, 381, 2, 4, 16, 80, 448, 2688, 2307, 2, 4, 16, 80, 448, 2688, 16896, 14589, 2, 4, 16, 80, 448, 2688, 16896, 109824, 95235, 2, 4, 16, 80, 448, 2688

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OFFSET

0,2

COMMENTS

The g.f. G(m,x) for column m=1,2,... of triangle A116880=CM(1,2) is x*(-sum(a(m,k)*x^(k-1),k=1..m) + sum(a(m,k)*x^k,k=0..m)*2*c(2*x))/(1+x), with the o.g.f. c(x) of A000108 (Catalan numbers).

LINKS

Table of n, a(n) for n=0..50.

W. Lang: First 10 rows.

FORMULA

a(m,m)= A064062(m) =:C(2;m), m>=0 and a(m,k)=2*A052701(k) = C(k)*2^(k+1), for k=1,...,m-1 and C(k):=A000108(k) (Catalan).

EXAMPLE

m=3: G(3,x)= x*(-(4+16*x+13*x^2) +

(2+4*x+16*x^2+13*x^3)*2*c(2*x))/(1+x).

CROSSREFS

Sequence in context: A133422 A331136 A099312 * A331499 A209128 A209131

Adjacent sequences: A117502 A117503 A117504 * A117506 A117507 A117508

KEYWORD

nonn,easy,tabl

AUTHOR

Wolfdieter Lang, Apr 13 2006

STATUS

approved