A140604 Least nontrivial number k such that the sum of the digits of k^k (mod k) == n.

1, 4, 55, 6, 7, 8, 12, 2236, 11, 15, 14, 20, 21, 17, 274, 35, 22, 44, 36, 82, 73, 41, 29, 28, 26, 115, 85, 98, 2054, 31, 46, 502, 40, 39, 79, 3248, 45, 38, 128, 64, 511, 80, 183, 83, 76, 47, 127, 176, 52, 70, 190, 57, 65, 425, 63, 56, 95, 59, 10327, 794, 1248, 89, 410, 69

Offset: 0

Author

Robert G. Wilson v, May 17 2008

Keywords

• base
• nonn

Examples

			1^1 (mod 1)==0; 4^4=256 so 13 (mod 4)==1; 55^55=... so 442 (mod 55)==2, 6^6=46656 so 27 (mod 6)==3; etc.
		

Links

• Robert G. Wilson v, Table of n, a(n) for n = 0..1000.

Crossrefs

Cf. A108827, A125526, A125724, A108825.

Programs

Mathematica

t = Table[0, {101}]; Do[ a = Mod[Plus @@ IntegerDigits[n^n], n]; If[a < 101 && t[[a + 1]] == 0, t[[a + 1]] = n; Print[{a, n}]], {n, 10000}]