A108859 Numbers k such that k divides the sum of the digits of k^(2k).

1, 3, 5, 9, 18, 63, 72, 74, 104, 111, 116, 117, 565, 621, 734, 1242, 1620, 4596, 4728, 5823, 5956, 21135, 28251, 46530, 46908, 78257, 129619, 277407

Offset

1,2

Comments

The quotients are 1, 6, 8, 9, 13, 17, 16, 17, 17, 18, 17, 19, 25, 25, 26, 28, 20, 33, 33, 34, 34, 39, 40, 33, 42, 44, 46, 49.

Links

Table of n, a(n) for n=1..28.

Example

734 is a term because the sum of the digits of 734^(2*734), 19084, is divisible by 734.

Mathematica

Do[If[Mod[Plus @@ IntegerDigits[n^(2*n)], n] == 0, Print[n]], {n, 1, 10000}]

Crossrefs

Sequence in context: A279634 A028411 A018098 * A032385 A218138 A192230

Adjacent sequences: A108856 A108857 A108858 * A108860 A108861 A108862

Keyword

base,hard,more,nonn

Author

Ryan Propper, Jul 11 2005

Extensions

a(22)-a(28) from Lars Blomberg, Jul 12 2011

Status

approved