A063992 Numbers that are not factorials.

3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78

Offset

1,1

Comments

The old entry with this sequence number was a duplicate of A002636.

A012245(a(n)) = 0. - Reinhard Zumkeller, Oct 11 2008

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Mathematica

With[{nn=5}, Complement[Range[nn!], Range[nn]!]] (* Harvey P. Dale, May 05 2019 *)

Prog

(PARI) { n=0; f=2; for (m=3, 10^9, g=f; f*=m; for (a=g + 1, f - 1, write("b063992.txt", n++, " ", a); if (n==1000, break)); if (n==1000, break) ) } \\ Harry J. Smith, Sep 05 2009
(Python)
def A063992(n):
    if n == 1: return 3
    i, j = 1, 1
    while j <= n:
        i += 1
        j *= i
    return (m:=n+i-1)+(m>=j) # Chai Wah Wu, Nov 05 2025

Crossrefs

Complement of A000142.

Sequence in context: A362580 A055495 A072442 * A324540 A171520 A039233

Adjacent sequences: A063989 A063990 A063991 * A063993 A063994 A063995

Keyword

nonn

Author

N. J. A. Sloane, Oct 11 2008

Status

approved