OFFSET
0,2
EXAMPLE
n=147 -> sigma(n)=1+3+7+21+49+147=228 Sum_digits(n)=1+4+7=12 -> 228/12 = 19
n=177 -> sigma(n)=1+3+59+177=240 Sum_digits(n)=1+7+7=15 -> 240/15 = 16
MAPLE
with(numtheory); P:=proc(n) local a, i, j, k, w; for i from 1 by 1 to n do w:=0; k:=i; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; j:=sigma(i)/w; if trunc(j)=j then print(j); fi; od; end: P(200);
MATHEMATICA
Select[Table[DivisorSigma[1, n]/Total[IntegerDigits[n]], {n, 300}], IntegerQ] (* Harvey P. Dale, Oct 01 2015 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paolo P. Lava and Giorgio Balzarotti, Aug 24 2007
STATUS
approved