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A108860 Numbers n such that n divides the sum of the digits of (2n)^n. 0
1, 3, 9, 12, 16, 18, 22, 27, 29, 33, 48, 54, 80, 127, 133, 149, 171, 335, 888, 1038, 1137, 1435, 1465, 1647, 13921, 14256, 22467, 22872, 23514, 23709, 39564, 108708, 108777, 109308, 230115 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The quotients are: 2, 3, 7, 6, 7, 7, 7, 8, 8, 9, 9, 9, 5, 11, 11, 11, 11, 8, 15, 15, 15, 11, 11, 16, 20, 20, 21, 21, 21, 21, 22, 24, 24, 24, 21.

LINKS

Table of n, a(n) for n=1..35.

EXAMPLE

888 is a term because the sum of the digits of (2*888)^888, 13320, is divisible by 888.

MATHEMATICA

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

PROG

(Python)

A108860_list = [n for n in range(1, 1000) if not sum(int(d) for d in str((2*n)**n)) % n] # Chai Wah Wu, Mar 15 2018

CROSSREFS

Sequence in context: A244147 A103531 A333441 * A006499 A310320 A274676

Adjacent sequences:  A108857 A108858 A108859 * A108861 A108862 A108863

KEYWORD

base,hard,more,nonn

AUTHOR

Ryan Propper, Jul 11 2005

EXTENSIONS

Two additional terms from Harvey P. Dale, Nov 24 2010

a(27)-a(35) from Lars Blomberg, Jul 02 2011

STATUS

approved

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Last modified April 14 09:23 EDT 2021. Contains 342948 sequences. (Running on oeis4.)