A085535 a(n) = (2n)^(2n-1).

2, 64, 7776, 2097152, 1000000000, 743008370688, 793714773254144, 1152921504606846976, 2185911559738696531968, 5242880000000000000000000, 15519448971100888972574851072, 55572324035428505185378394701824, 236773830007967588876795164938469376

Offset: 1

Author

N. J. A. Sloane, Jul 05 2003

Keywords

• nonn

Comments

a(0) is 0^(-1) = 1/0, which is undefined.

Crossrefs

Cf. A005408, A005843, A222621, A338167.

Programs

Mathematica

Table[(2*n)^(2*n - 1), {n, 20}] (* T. D. Noe, Feb 26 2013 *)

Formula

a(n) = A005843(n)^A005408(n-1). - Michel Marcus, Apr 14 2018

Sum_{n>=1} 1/a(n) = A338167. - Amiram Eldar, Nov 29 2020