|
| |
|
|
A038178
|
|
n = (sum of digits of n)^(number of digits of n).
|
|
1
| |
|
|
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 81, 512, 2401
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
COMMENTS
| Subset of A023106. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 20 2008]
|
|
|
FORMULA
| a(n) = (1/10)*(n-(n mod 10))*(729*n^2-14879*n+75971)+(n mod 10) - Rolf Pleisch (r_pleisch(AT)gmx.ch), Feb 06 2008
|
|
|
EXAMPLE
| n=512 is OK because (5+1+2)^3 = 512.
|
|
|
MATHEMATICA
| Select[Range[2500], #==Total[IntegerDigits[#]]^IntegerLength[#]&] (* From Harvey P. Dale, Oct 26 2011 *)
|
|
|
CROSSREFS
| Sequence in context: A153670 A024663 A193757 * A023106 A135480 A098766
Adjacent sequences: A038175 A038176 A038177 * A038179 A038180 A038181
|
|
|
KEYWORD
| nonn,nice,fini,full,base
|
|
|
AUTHOR
| Felice Russo (frusso(AT)micron.com)
|
|
|
EXTENSIONS
| 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)
|
| |
|
|
