A110139 - OEIS

%I #8 Jan 18 2023 14:24:12

%S 1,1,1,1,4,4,27,27,256,256,3125,3125,46656,46656,823543,823543,

%T 16777216,16777216,387420489,387420489,10000000000,10000000000,

%U 285311670611,285311670611,8916100448256,8916100448256,302875106592253

%N a(n) = floor(n/2)^floor(n/2).

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

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

%o (Python)

%o def A110139(n): return (m:=n>>1)**m # _Chai Wah Wu_, Jan 18 2023

%Y Cf. A000312.

%K easy,nonn

%O 0,5

%A _Paul Barry_, Jul 13 2005