A275822 Alternating sums of the cubes of the central binomial coefficients.
1, 7, 209, 7791, 335209, 15667799, 773221225, 39651016343, 2092095886657, 112840936041343, 6193764391911873, 344853399798469695, 19429178297906958721, 1105629520934309041279, 63455683531507986958721, 3668895994183490904049279
Offset: 0
Keywords
Links
- Robert Israel, Table of n, a(n) for n = 0..555
- The Wolfram Functions Site, Complete Elliptic Integrals
Crossrefs
Cf. A079727.
Programs
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Maple
L:= [seq((-1)^k*binomial(2*k,k)^3,k=0..20)]: B:= ListTools:-PartialSums(L): seq((-1)^(k+1)*B[k],k=1..nops(B)); # Robert Israel, Nov 21 2016
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Mathematica
Table[Sum[Binomial[2 k, k]^3 (-1)^(n - k), {k, 0, n}], {n, 0, 20}] Table[Sum[(-1)^(n - k) (k + 1)^3 CatalanNumber[k]^3, {k, 0, n}], {n, 0, 20}] (* Jan Mangaldan, Jul 07 2020 *)
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Maxima
makelist(sum(binomial(2*k,k)^3*(-1)^(n-k),k,0,n),n,0,12);
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PARI
a(n) = sum(k=0, n, (-1)^(n-k)*binomial(2*k,k)^3); \\ Michel Marcus, Jul 07 2020
Formula
a(n) = Sum_{k=0..n} (-1)^(n-k)*binomial(2*k,k)^3.
Recurrence: (n+2)^3*a(n+2)-(3*n+4)*(21*n^2+66*n+52)*a(n+1)-8*(2n+3)^3*a(n)=0.
G.f.: (4/Pi^2)*K((1-sqrt(1-64*t))/2)^2/(1+t), where K(x) is complete elliptic integral of the first kind (defined as in The Wolfram Functions Site).
a(n) ~ 2^(6*n+6) / (65*Pi^(3/2)*n^(3/2)). - Vaclav Kotesovec, Nov 16 2016