OFFSET
1,3
EXAMPLE
For n = 1,2,3,4,5,6, the digit-sum of 2^n is 2,4,8,7,5,10, so
a(1) through a(6) are 0,0,2,3,0,4. - N. J. A. Sloane, Aug 12 2014
MATHEMATICA
Table[Mod[Total[IntegerDigits[2^n]], n], {n, 100}] (* Harvey P. Dale, Aug 12 2014 *)
CROSSREFS
Sum of digits of k^n mod n: (k=2) A000079, A001370, A175434, A175169; (k=3) A000244, A004166, A175435, A067862; (k=5) A000351, A066001, A175456; (k=6) A000400, A066002, A175457, A067864; (k=7) A000420, A066003, A175512, A067863; (k=8) A062933; (k=13) A001022, A175527, A175528, A175525; (k=21) A175589; (k=167) A175558, A175559, A175560, A175552.
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Dec 03 2010
EXTENSIONS
Offset changed to 1 at the suggestion of Harvey P. Dale, Aug 12 2014
STATUS
approved