A226971 Numbers k such that the sum of digits of k^7 is equal to k.

0, 1, 18, 27, 31, 34, 43, 53, 58, 68

Offset: 1

Author

Michel Lagneau, Jun 24 2013

Keywords

• nonn
• base
• fini
• full

Comments

Only the ten integers listed have this property.

Examples

			a(3) = 18 because 18^7 = 612220032 and 6+1+2+2+2+0+0+3+2 = 18.
		

Crossrefs

Cf. A046459, A055575, A055576, A055577.

Cf. A152147.

Programs

Magma

[n: n in [0..80] | &+Intseq(n^7) eq n]; // Vincenzo Librandi, Feb 23 2015

Mathematica

Select[Range[0, 100], #==Total[IntegerDigits[#^7]]&]

PARI

isok(k)=sumdigits(k^7)==k \\ Patrick De Geest, Dec 13 2024

Sage

[n for n in (0..70) if sum((n^7).digits()) == n] # Bruno Berselli, Feb 23 2015