OFFSET
1,1
COMMENTS
The sequence is a subset of Niven (or Harshad) numbers A005349.
FORMULA
Positive integers n such that A195860(n) = 2.
EXAMPLE
7 can be divided only for 7^1; 7^2 = 49, sum_digits(49) = 13, and 49 is not a multiple of 13.
MAPLE
readlib(log10); P:=proc(n, m) local a, i, k, w, x, ok; for i from 1 by 1 to n do a:=simplify(log10(i)); if not (trunc(a)=a) then ok:=1; x:=1; while ok=1 do w:=0; k:=i^x; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; if trunc(i^x/w)=i^x/w then x:=x+1; else if x-1=m then print(i); fi; ok:=0; fi; od; fi; od; end: P(2000, 1);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Paolo P. Lava & Giorgio Balzarotti, Nov 22 2007
EXTENSIONS
Definition edited by N. J. A. Sloane, Sep 04 2010
STATUS
approved