A316663 a(n) = floor(sqrt((2*n)^(n+1))).

0, 2, 8, 36, 181, 1000, 5985, 38416, 262144, 1889568, 14310835, 113379904, 936209559, 8031810176, 71397866601, 656100000000, 6219777023950, 60716992766464, 609359740010496, 6278211847988224, 66317769195774370, 717368321110468608, 7937902853812916501, 89762301673555234816, 1036371513660502339855

Offset: 0

Author

Greg Huber, Jul 09 2018

Keywords

• nonn
• easy

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..500

Crossrefs

Cf. A000196, A085532, A316661.

Programs

PARI

a(n)=sqrtint((2*n)^(n+1)) \\ Andrew Howroyd, Jan 15 2025

Formula

a(n) = A000196(A085532(n)). - Andrew Howroyd, Jan 15 2025