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A147725 Row sums of triangle in A147724. 1
1, 2, 10, 68, 502, 3770, 28408, 214202, 1615330, 12181748, 91867102, 692804690, 5224704088, 39401485202, 297141621850, 2240858259428, 16899166494502, 127443057596810, 961096686931768, 7247996548821002, 54659905383139570 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

FORMULA

a(n)=9*a(n-1)-11*a(n-2) for n>2, a(0)=1, a(1)=2, a(2)=10. G.f.: (1-7x+3x^2)/(1-9x+11x^2).

a(n)=[(9/2)+(1/2)*sqrt(37)]^(n-1)-(1/37)*sqrt(37)*[(9/2)-(1/2)*sqrt(37)]^(n-1)+(1/37)*[(9/2)+(1/2) *sqrt(37)]^(n-1)*sqrt(37)+[(9/2)-(1/2)*sqrt(37)]^(n-1)+(3/11)*[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava, Nov 18 2008]

CROSSREFS

Sequence in context: A208561 A152620 A152621 * A074603 A110520 A136633

Adjacent sequences:  A147722 A147723 A147724 * A147726 A147727 A147728

KEYWORD

nonn

AUTHOR

Philippe Deléham, Nov 15 2008

STATUS

approved

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Last modified October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)