A066210 a(n) = ((2*n)^(2*n+2) - 1)/(4*n^2 - 1).

1, 5, 273, 47989, 17043521, 10101010101, 8978450801041, 11168991475945493, 18519084246547628289, 39468223580173616639125, 105120401002506265664160401, 342134767379466388778420319285, 1336055317331762879448123353666113, 6165239757363019766071928620679315189

Offset

0,2

Links

Harry J. Smith, Table of n, a(n) for n = 0..100

Mathematica

Table[((2n)^(2n+2)-1)/(4n^2-1), {n, 0, 20}] (* Harvey P. Dale, Jan 18 2020 *)

Prog

(PARI) a(n) = { ((2*n)^(2*n+2)-1)/(4*n^2-1) } \\ Harry J. Smith, Feb 06 2010
(Magma) [((2*n)^(2*n+2) - 1)/(4*n^2 - 1): n in [0..12]]; // Vincenzo Librandi, Jan 19 2020

Crossrefs

Sequence in context: A153322 A326321 A234324 * A036213 A262548 A112901

Adjacent sequences: A066207 A066208 A066209 * A066211 A066212 A066213

Keyword

nonn

Author

N. J. A. Sloane, Dec 17 2001

Status

approved