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A124359
Numbers n for which the sum of the digits of n^k, for some k, is equal to n.
10
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 17, 18, 20, 22, 25, 26, 27, 28, 31, 34, 35, 36, 40, 43, 45, 46, 53, 54, 58, 63, 64, 68, 71, 80, 81, 82, 85, 86, 90, 91, 94, 97, 98, 103, 104, 106, 107, 108, 117, 118, 126, 127, 133, 134, 135, 136, 140, 142, 143, 146, 152, 154, 155, 157, 160, 163, 169, 170
OFFSET
1,3
COMMENTS
Most of the values are conjectural. So far not much is proved about the function A247889. - M. F. Hasler and Robert Israel, May 18 2017
EXAMPLE
18^3 = 5832 and 5 + 8 + 3 + 2 = 18 (also 18^6 = 34012224 and 18^7 = 612220032).
Again 46^5 = 205962976 and 2 + 0 + 5 + 9 + 6 + 2 + 9 + 7 + 6 = 46.
PROG
(PARI) for(n=0, 199, if(A247889(n), print1(n, ", "))) \\ Derek Orr, Sep 25 2014
(PARI) select(A247889, [0..170]) \\ M. F. Hasler, May 18 2017
CROSSREFS
Complement of A124367. Numbers for which A247889 is nonzero.
Sequence in context: A179977 A326298 A372281 * A124366 A289868 A304247
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
Prepended a(1) = 0, offset corrected and more terms added by Derek Orr, Sep 25 2014
Edited by M. F. Hasler, May 18 2017
STATUS
approved