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A109658 Numbers n such that the sum of the digits of n^sigma(n) is divisible by n. 0
1, 2, 3, 9, 11, 18, 54, 74, 108, 135, 426, 531, 585, 1361, 3456, 6771, 7245, 7392, 11025, 11957, 21494, 27063, 41952, 68494, 72516 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

EXAMPLE

The sum of the integer digits of 531^sigma(531) is 9558 and 9558 is divisible by 531, so 531 is in the sequence.

MATHEMATICA

Do[s = n^DivisorSigma[1, n]; k = Plus @@ IntegerDigits[s]; If[Mod[k, n] == 0, Print[n]], {n, 1, 10000}]

CROSSREFS

Sequence in context: A110772 A074338 A111319 * A110350 A057569 A177950

Adjacent sequences:  A109655 A109656 A109657 * A109659 A109660 A109661

KEYWORD

base,nonn

AUTHOR

Ryan Propper (rpropper(AT)stanford.edu), Aug 06 2005

EXTENSIONS

More terms from Ryan Propper (rpropper(AT)stanford.edu), Oct 10 2005

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Last modified February 17 04:58 EST 2012. Contains 205985 sequences.