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A238755
Second convolution of A065096.
1
0, 0, 1, 12, 98, 684, 4403, 27048, 161412, 945288, 5466549, 31340628, 178604998, 1013573652, 5735117479, 32385232272, 182622362504, 1028897389008, 5793703249449, 32615362319580, 183593293074730, 1033535639454780, 5819389057957211, 32775522041862072, 184658694508103180
OFFSET
0,4
FORMULA
G.f. = (G.f. of A065096)^2.
Recurrence: (n+6)*a(n) = 225*(6-n)*a(n-8) + 1020*(2*n-9)*a(n-7) + 5164*(3-n)*a(n-6) + 76*(78*n-117)*a(n-5) - 3590*n*a(n-4) + 36*(34*n+51)*a(n-3) - 236*(n+3)*a(n-2) + 12*(2*n+9)*a(n-1), n>=8.
Recurrence (of order 2): (n-2)*(n+6)*a(n) = 3*(n+1)*(2*n+3)*a(n-1) - n*(n+1)*a(n-2). - Vaclav Kotesovec, Mar 05 2014
a(n) ~ (3*sqrt(2)-4)^(7/2) * (3+2*sqrt(2))^(n+6) / (8*sqrt(Pi)*n^(3/2)). - Vaclav Kotesovec, Mar 05 2014
MATHEMATICA
CoefficientList[Series[(1-3*x-Sqrt[1-6*x+x^2])^4/(16*x^3)^2, {x, 0, 20}], x] (* Vaclav Kotesovec, Mar 05 2014 *)
PROG
(PARI) x='x+O('x^50); concat([0, 0], Vec((1-3*x-sqrt(1-6*x+x^2))^4/(16*x^3)^2)) \\ G. C. Greubel, Apr 05 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Fung Lam, Mar 04 2014
STATUS
approved