Armstrong Number

The $n$-digit numbers equal to sum of $n$th powers of their digits (a finite sequence), also called Plus Perfect Numbers. They first few are given by 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407, 1634, 8208, 9474, 54748, ... (Sloane's A005188).

See also Narcissistic Number

References

Sloane, N. J. A. Sequence A005188/M0488 in ``An On-Line Version of the Encyclopedia of Integer Sequences.'' http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S. The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.