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

0,3

Links

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

Formula

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

Example

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

Mathematica

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

Prog

(Sage) [floor(n^n/2) for n in range(0, 17)] # Zerinvary Lajos, Dec 02 2009
(PARI) a(n) = n^n\2; \\ Michel Marcus, Feb 18 2016
(Magma) [Floor(n^n/2): n in [0..20]]; // Vincenzo Librandi, Feb 18 2016

Crossrefs

Cf. A000312.

Sequence in context: A108471 A036078 A290219 * A259611 A351299 A215624

Adjacent sequences: A057062 A057063 A057064 * A057066 A057067 A057068

Keyword

nonn

Author

Henry Bottomley, Jul 31 2000

Extensions

More terms from Harvey P. Dale, May 19 2012

Status

approved