OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..833
FORMULA
Recurrence: n^2*a(n) = (3*n-2)*(5*n-2)*a(n-1) + 4*(2*n-1)^2*a(n-2).
a(n) ~ 16^(n+1)/(17*Pi*n).
MAPLE
series(2*EllipticK(4*x^(1/2))/(Pi*(1+x)), x=0, 20)
MATHEMATICA
Table[Sum[(-1)^(n-k)*Binomial[2*k, k]^2, {k, 0, n}], {n, 0, 20}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vaclav Kotesovec, Aug 07 2013
STATUS
approved