A271669 Smallest k > n such that n divides k and n^k == n (mod k).

2, 161038, 6, 12, 10, 30, 14, 56, 18, 30, 22, 132, 26, 182, 30, 48, 34, 306, 38, 380, 42, 66, 46, 552, 50, 130, 54, 84, 58, 870, 62, 992, 66, 102, 70, 180, 74, 1406, 78, 120, 82, 1722, 86, 1892, 90, 138, 94, 2256, 98, 350, 102, 156, 106, 2862, 110, 280, 114, 174, 118, 3540

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = 2n for odd n. - Robert Israel, Apr 12 2016

a(n) = n * A102457(n) for n > 1. - Thomas Ordowski, Apr 13 2016

Example

Because of the definition of (pseudo)primes to base 2, a(2) is the least element of A006935 greater than 2. - Altug Alkan, Apr 12 2016

Mathematica

Table[SelectFirst[Range[n + 1, 10^6], Function[k, Divisible[k, n] && PowerMod[n, k, k] == Mod[n, k]]], {n, 60}] (* Michael De Vlieger, Apr 12 2016, Version 10 *)

Prog

(PARI) a(n) = {k = n+1; while( !(((k % n)==0) && (Mod(n, k)^k == Mod(n, k))), k++); k; } \\ Michel Marcus, Apr 12 2016

Crossrefs

Cf. A006935, A102457.

Sequence in context: A324438 A167518 A178168 * A006935 A070833 A176584

Adjacent sequences: A271666 A271667 A271668 * A271670 A271671 A271672

Keyword

nonn

Author

Thomas Ordowski, Apr 12 2016

Extensions

More terms from Michel Marcus, Apr 12 2016

Status

approved