A284999 Ceiling(Gamma(2n/3)).

2, 1, 1, 2, 3, 6, 15, 41, 120, 390, 1356, 5040, 19885, 82835, 362880, 1665838, 7988888, 39916800, 207304279, 1116669004, 6227020800, 35886673907, 213407853923, 1307674368000, 8245960182039, 53446811415730, 355687428096000, 2427977164711193, 16984208960998390

Offset

1,1

Comments

There are two integer-valued interpolations between successive factorials.

Links

Clark Kimberling, Table of n, a(n) for n = 1..1000

Formula

a(n) = ceiling(Gamma(2n/3)).

Mathematica

Table[Ceiling[Gamma[2n/3]], {n, 1, 35}]

Crossrefs

Cf. A000142, A284998.

Sequence in context: A212359 A130030 A088022 * A016732 A077948 A077971

Adjacent sequences: A284996 A284997 A284998 * A285000 A285001 A285002

Keyword

nonn,easy

Author

Clark Kimberling, Apr 08 2017

Status

approved