A056981 a(n) = A002596(n)^2.

1, 1, 1, 1, 25, 49, 441, 1089, 184041, 511225, 5909761, 17631601, 863948449, 2704312009, 34493775625, 111759833025, 93990019574025, 312541206957225, 4201942893536025, 14258670483605625, 780804795682244025

Offset

0,5

Comments

Numerator of h^(2n) in the Kummer-Gauss series for the perimeter of an ellipse.

Links

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

Eric Weisstein's World of Mathematics, Gauss-Kummer Series.

Eric Weisstein's World of Mathematics, Ellipse.

Mathematica

Numerator[Table[Binomial[1/2, n]^2, {n, 50}]] (* Artur Jasinski, Aug 30 2016 *)

Crossrefs

Cf. A002596, A056982.

Sequence in context: A146641 A171590 A322434 * A132585 A049228 A309828

Adjacent sequences: A056978 A056979 A056980 * A056982 A056983 A056984

Keyword

nonn,frac

Author

Eric W. Weisstein

Extensions

New description from N. J. A. Sloane, Feb 18 2004

Status

approved