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A226971
Numbers k such that the sum of digits of k^7 is equal to k.
2
0, 1, 18, 27, 31, 34, 43, 53, 58, 68
OFFSET
1,3
COMMENTS
Only the ten integers listed have this property.
EXAMPLE
a(3) = 18 because 18^7 = 612220032 and 6+1+2+2+2+0+0+3+2 = 18.
MATHEMATICA
Select[Range[0, 100], #==Total[IntegerDigits[#^7]]&]
PROG
(Magma) [n: n in [0..80] | &+Intseq(n^7) eq n]; // Vincenzo Librandi, Feb 23 2015
(Sage) [n for n in (0..70) if sum((n^7).digits()) == n] # Bruno Berselli, Feb 23 2015
CROSSREFS
KEYWORD
nonn,base,fini,full
AUTHOR
Michel Lagneau, Jun 24 2013
STATUS
approved