A057065 a(n) = floor(n^n/2).

0, 0, 2, 13, 128, 1562, 23328, 411771, 8388608, 193710244, 5000000000, 142655835305, 4458050224128, 151437553296126, 5556003412779008, 218946945190429687, 9223372036854775808, 413620130943168382088, 19673204037648268787712, 989209827830156794561989

Offset: 0

Author

Henry Bottomley, Jul 31 2000

Keywords

• nonn

Examples

			a(5) = floor(5^5/2) = floor(3125/2) = 1562.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..300

Crossrefs

Cf. A000312.

Programs

Magma

[Floor(n^n/2): n in [0..20]]; // Vincenzo Librandi, Feb 18 2016

Mathematica

Join[{0}, Table[Floor[n^n/2], {n, 20}]] (* Harvey P. Dale, May 19 2012 *)

PARI

a(n) = n^n\2; \\ Michel Marcus, Feb 18 2016

Sage

[floor(n^n/2) for n in range(0,17)] # Zerinvary Lajos, Dec 02 2009

Formula

a(n) = floor( A000312(n)/2 ).

Extensions

More terms from Harvey P. Dale, May 19 2012