A235600 a(n) = n/d(n) if d(n) divides n, otherwise a(n) = n, where d(n) is the sum of the digits of n (A007953).

1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 11, 4, 13, 14, 15, 16, 17, 2, 19, 10, 7, 22, 23, 4, 25, 26, 3, 28, 29, 10, 31, 32, 33, 34, 35, 4, 37, 38, 39, 10, 41, 7, 43, 44, 5, 46, 47, 4, 49, 10, 51, 52, 53, 6, 55, 56, 57, 58, 59, 10, 61, 62, 7, 64, 65, 66, 67, 68, 69, 10, 71, 8, 73, 74, 75, 76, 77, 78, 79, 10, 9, 82, 83, 7, 85

Offset: 1

Author

N. J. A. Sloane, Jan 18 2014

Keywords

• nonn
• base

Links

• Paolo Xausa, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007953, A235601, A235602.

Cf. A065517 (first differs at n=15).

Programs

Mathematica

A235600[n_]:=With[{d=Total[IntegerDigits[n]]},If[Divisible[n,d],n/d,n]];
Array[A235600,100] (* Paolo Xausa, Dec 06 2023 *)

PARI

a(n) = my(s=sumdigits(n)); if (n % s, n, n/s); \\ Michel Marcus, Jul 15 2021