A132628 Numbers n for which the sum of their digits divides sigma(n).

1, 6, 10, 11, 15, 19, 20, 22, 24, 30, 31, 33, 35, 42, 51, 52, 60, 62, 66, 68, 71, 79, 87, 90, 100, 101, 102, 103, 104, 105, 109, 110, 112, 114, 118, 120, 123, 124, 130, 132, 136, 138, 141, 143, 145, 147, 150, 153, 160, 161, 165, 167, 168, 174, 177, 190, 194, 198

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

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(i, j); fi; od; end: P(200)

Mathematica

Select[Range[200], Divisible[DivisorSigma[1, #], Total[IntegerDigits[#]]]&] (* Harvey P. Dale, Dec 06 2012 *)

Crossrefs

Cf. A007691, A054030, A132629.

Sequence in context: A107014 A206036 A349761 * A288928 A039509 A277597

Adjacent sequences: A132625 A132626 A132627 * A132629 A132630 A132631

Keyword

nonn,base,easy

Author

Paolo P. Lava and Giorgio Balzarotti, Aug 24 2007

Status

approved