A261779 a(n) = ceiling((n-1)! / n).

1, 1, 1, 2, 5, 20, 103, 630, 4480, 36288, 329891, 3326400, 36846277, 444787200, 5811886080, 81729648000, 1230752346353, 19760412672000, 336967037143579, 6082255020441600, 115852476579840000, 2322315553259520000, 48869596859895986087, 1077167364120207360000, 24817936069329577574400, 596585001666576384000000

Offset

1,4

Comments

Except for n = 4, this is ((n-1)!+1)/n for prime n, and (n-1)!/n otherwise.

Links

Table of n, a(n) for n=1..26.

Mathematica

Table[Ceiling[((n-1)!)/n], {n, 30}] (* Harvey P. Dale, Oct 04 2018 *)

Prog

(PARI) a(n) = ceil((n-1)!/n)

Crossrefs

Cf. A007619 (prime index elements).

Sequence in context: A006924 A212580 A370669 * A227096 A152562 A006867

Adjacent sequences: A261776 A261777 A261778 * A261780 A261781 A261782

Keyword

nonn

Author

Franklin T. Adams-Watters, Aug 31 2015

Status

approved