A038204 Least k such that factorials have exactly n distinct residues mod k.

1, 2, 3, 5, 7, 11, 22, 25, 55, 13, 26, 17, 34, 57, 76, 95, 23, 46, 29, 58, 31, 62, 93, 155, 319, 37, 74, 129, 41, 82, 47, 94, 141, 235, 53, 106, 59, 118, 71, 142, 61, 67, 134, 73, 146, 219, 365, 511, 79, 158, 237, 395, 553, 1241, 83, 166, 332, 747, 89, 178, 291, 485

Offset

1,2

Links

David W. Wilson, Table of n, a(n) for n = 1..10000

Mathematica

s = Table[Length@ Union@ Mod[Range[10^3]!, n], {n, 2000}]; Table[FirstPosition[s, n], {n, 62}] // Flatten (* Michael De Vlieger, Aug 03 2016, Version 10 *)

Prog

(PARI) a(n)=my(k=n, t=1); while(#Set(vector(k, i, t=(t*i)%k))!=n, k++; t=1); k \\ Charles R Greathouse IV, Aug 03 2016

Crossrefs

Cf. A038203.

Sequence in context: A072299 A334199 A297026 * A075049 A361820 A061165

Adjacent sequences: A038201 A038202 A038203 * A038205 A038206 A038207

Keyword

nonn

Author

David W. Wilson

Status

approved