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A026765 T(n,0) + T(n,1) + ... + T(n,n), T given by A026758. 2
1, 2, 4, 9, 18, 41, 82, 188, 376, 867, 1734, 4020, 8040, 18735, 37470, 87735, 175470, 412715, 825430, 1949624, 3899248, 9245721, 18491442, 44003717, 88007434, 210121733, 420243466, 1006390014, 2012780028, 4833517551 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..29.

FORMULA

Conjecture: G.f.:-1/2*(1-2*x-5*x^2+10*x^3-(1-10*x^2+29*x^4-20*x^6)^(1/2))/x/(1-2*x-5*x^2+10*x^3) [From Maksym Voznyy (voznyy(AT)mail.ru), Aug 11 2009]

Conjecture: (n+1)*a(n) -2*a(n-1) +2*(-5*n+3)*a(n-2) +12*a(n-3) +(29*n-71)*a(n-4) -10*a(n-5) +20*(-n+5)*a(n-6)=0. - R. J. Mathar, Jun 30 2013

Conjecture: a(n) ~ (2+sqrt(5) + (-1)^n*(2-sqrt(5))) * 5^(n/2) / sqrt(2*Pi*n). - Vaclav Kotesovec, Feb 12 2014

CROSSREFS

Sequence in context: A026732 A171003 A094291 * A264649 A259803 A032175

Adjacent sequences:  A026762 A026763 A026764 * A026766 A026767 A026768

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified May 27 07:44 EDT 2019. Contains 323599 sequences. (Running on oeis4.)