A038178 Numbers k such that k = (sum of digits of k)^(number of digits of k).

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 81, 512, 2401

Offset

1,3

Comments

To prove completeness, consider that k^m contains more than m digits for every k >= 10 and check 1 <= k <= 9 explicitly. - Ulrich Schimke (ulrschimke(AT)aol.com)

Subset of A023106. - R. J. Mathar, Oct 20 2008

Links

Table of n, a(n) for n=1..13.

Example

512 is in the sequence because (5 + 1 + 2)^3 = 512.

Mathematica

Select[Range[2500], #==Total[IntegerDigits[#]]^IntegerLength[#]&] (* Harvey P. Dale, Oct 26 2011 *)

Crossrefs

Cf. A007953, A055642, A023106.

Sequence in context: A237346 A193757 A246605 * A023106 A135480 A289979

Adjacent sequences: A038175 A038176 A038177 * A038179 A038180 A038181

Keyword

nonn,nice,fini,full,base

Author

Felice Russo

Status

approved