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A247102 G.f.: (6*x+2)/(sqrt(-3*x^2-6*x+1)*(4*x^2+4*x))-(2*x+1)/(2*x^2+2*x). 0
2, 10, 53, 298, 1727, 10207, 61154, 370090, 2256983, 13848085, 85387040, 528646015, 3284180720, 20462505850, 127816245053, 800143927210, 5018683475087, 31532297088781, 198419993271440, 1250291989478773, 7888160383113014 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

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

FORMULA

a(n) = sum(i=0..n+1, binomial(2*n-i+1,n-i+1)*sum(j=0..n+1, binomial(j,-j+i)* binomial(n+1,j)).

a(n) ~ sqrt(3) * (3+2*sqrt(3))^(n+1) / (2*sqrt(2*Pi*n)). - Vaclav Kotesovec, Nov 23 2014

MATHEMATICA

CoefficientList[Series[(6 x + 2) / (Sqrt[-3 x^2 - 6 x + 1] (4 x^2 + 4 x)) - (2 x + 1) / (2 x^2 + 2 x), {x, 0, 40}], x] (* Vincenzo Librandi, Nov 22 2014 *)

PROG

(Maxima)

a(n):=sum(binomial(2*n-i+1, n-i+1)*sum(binomial(j, -j+i)*binomial(n+1, j), j, 0, n+1), i, 0, n+1);

CROSSREFS

Sequence in context: A037724 A037619 A221610 * A009320 A204186 A009322

Adjacent sequences:  A247099 A247100 A247101 * A247103 A247104 A247105

KEYWORD

nonn

AUTHOR

Vladimir Kruchinin, Nov 22 2014

STATUS

approved

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Last modified February 19 02:06 EST 2018. Contains 299330 sequences. (Running on oeis4.)