OFFSET
0,2
COMMENTS
All terms are both perfect squares and numbers of the form n^n. - William Boyles, Jul 31 2015
The number of sequences of length 2n using 2n symbols. - Washington Bomfim, Jan 14 2020
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..100
FORMULA
a(n) = A000312(2*n). - Michel Marcus, Jul 31 2015
a(n) = A062971(n)^2. - Michel Marcus, Aug 04 2015
a(n) = [x^(2*n)] 1/(1 - 2*n*x). - Ilya Gutkovskiy, Oct 10 2017
MATHEMATICA
{1}~Join~Table[(2 n)^(2 n), {n, 1, 4!}] (* Michael De Vlieger, Aug 04 2015 *)
PROG
(Python)
def A085534(n): return (m:=n<<1)**m # Chai Wah Wu, Nov 18 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 05 2003
STATUS
approved