A132629 Sigma(n)/Sum_digits(n) for n such that sigma(n) is divisible by Sum_digits(n).

1, 2, 18, 6, 4, 2, 21, 9, 10, 24, 8, 8, 6, 16, 12, 14, 28, 12, 12, 9, 9, 5, 8, 26, 217, 51, 72, 26, 42, 32, 11, 108, 62, 40, 18, 120, 28, 32, 63, 56, 27, 24, 32, 21, 18, 19, 62, 26, 54, 24, 24, 12, 32, 30, 16, 36, 21, 26

Offset

0,2

Links

Table of n, a(n) for n=0..57.

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

Cf. A007691, A054030, A132628.

Sequence in context: A179073 A087665 A093481 * A288161 A302454 A303236

Adjacent sequences: A132626 A132627 A132628 * A132630 A132631 A132632

Keyword

easy,nonn

Author

Paolo P. Lava and Giorgio Balzarotti, Aug 24 2007

Status

approved