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A118347 Semi-diagonal (one row below central terms) of pendular triangle A118345 and equal to the self-convolution of the central terms (A118346). 3
1, 2, 11, 70, 487, 3592, 27600, 218566, 1771367, 14621410, 122495659, 1038934480, 8903129300, 76970244560, 670507216168, 5879770542870, 51861650744071, 459804626981158, 4095433894576785, 36628711884398086, 328824295880947471 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..20.

PROG

(PARI) {a(n)=polcoeff((serreverse(x*(1-2*x+sqrt((1-2*x)*(1-6*x)+x*O(x^n)))/2/(1-2*x))/x)^2, n)}

CROSSREFS

Cf. A118345, A118346, A118348, A118349.

Sequence in context: A274736 A229230 A135166 * A250887 A334048 A047776

Adjacent sequences:  A118344 A118345 A118346 * A118348 A118349 A118350

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Apr 26 2006

STATUS

approved

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Last modified January 20 04:18 EST 2021. Contains 340301 sequences. (Running on oeis4.)