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A119243 Eigenvector of triangle A118919, so that a(n) = Sum_{k=0..[n\2]} A118919(n,k)*a(k). 2
1, 2, 7, 26, 103, 422, 1768, 7520, 32335, 140174, 611530, 2681516, 11807683, 52177166, 231262945, 1027703054, 4577477065, 20429990450, 91348096963, 409110897122, 1834954888618, 8241277167236, 37059369415102 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Equals the self-convolution of A119244, which is the eigenvector of triangle A119245.

LINKS

Table of n, a(n) for n=0..22.

FORMULA

G.f. A(x) satisfies: A(x) = A(-x/(1-4*x))/(1-4*x). Eigenvector: a(n) = Sum_{k=0..[n\2]} a(k)*(2*k+1)*C(2*n+2,n-2*k)/(n+1) for n>=0, with a(0)=1.

PROG

(PARI) {a(n)=if(n==0, 1, sum(k=0, n\2, a(k)*(2*k+1)*binomial(2*n+2, n-2*k)/(n+1)))}

CROSSREFS

Cf. A118919, A119244 (A(x)^(1/2)).

Sequence in context: A271844 A198957 A150537 * A264224 A150538 A150539

Adjacent sequences:  A119240 A119241 A119242 * A119244 A119245 A119246

KEYWORD

nonn

AUTHOR

Paul D. Hanna, May 10 2006

STATUS

approved

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Last modified May 14 13:50 EDT 2021. Contains 343884 sequences. (Running on oeis4.)