|
Search: id:A109658
|
|
|
| A109658 |
|
Numbers n such that the sum of the digits of n^sigma(n) is divisible by n. |
|
+0
1
|
|
| 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; listen)
|
|
|
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 this_sequence A110350 A057569 A049618
Adjacent sequences: A109655 A109656 A109657 this_sequence 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
|
|
|
Search completed in 0.005 seconds
|
