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A109659 Numbers n such that the sum of the digits of sigma(n)^n is divisible by n. 0
1, 15, 20, 34, 42, 44, 50, 101, 107, 558, 584, 750, 1491, 2793, 2889, 15811, 27285 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Next term after 2889, if it exists, is greater than 10000.

Next term if it exists, is greater than 30000. [From Sean A. Irvine, Feb 24 2010]

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

The digits of sigma(1491)^1491 sum to 22365 and 22365 is divisible by 1491, so 1491 is in the sequence.

MATHEMATICA

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

CROSSREFS

Sequence in context: A086770 A111200 A088494 * A294149 A065148 A093028

Adjacent sequences:  A109656 A109657 A109658 * A109660 A109661 A109662

KEYWORD

base,more,nonn

AUTHOR

Ryan Propper, Aug 06 2005

EXTENSIONS

Two more terms from Sean A. Irvine, Feb 24 2010

STATUS

approved

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Last modified December 15 20:00 EST 2019. Contains 330000 sequences. (Running on oeis4.)