A110139 a(n) = floor(n/2)^floor(n/2).

1, 1, 1, 1, 4, 4, 27, 27, 256, 256, 3125, 3125, 46656, 46656, 823543, 823543, 16777216, 16777216, 387420489, 387420489, 10000000000, 10000000000, 285311670611, 285311670611, 8916100448256, 8916100448256, 302875106592253

Offset

0,5

Links

Table of n, a(n) for n=0..26.

Formula

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

a(2n) = a(2n+1) = n^n = A000312(n).

Prog

(Python)
def A110139(n): return (m:=n>>1)**m # Chai Wah Wu, Jan 18 2023

Crossrefs

Cf. A000312.

Sequence in context: A117429 A132650 A112953 * A078146 A066836 A227715

Adjacent sequences: A110136 A110137 A110138 * A110140 A110141 A110142

Keyword

easy,nonn

Author

Paul Barry, Jul 13 2005

Status

approved