A131930 Numbers k such that the decimal representation of k contains at least one prime factor of k.

2, 3, 5, 7, 11, 12, 13, 15, 17, 19, 20, 22, 23, 24, 25, 26, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 41, 42, 43, 45, 47, 50, 52, 53, 55, 59, 61, 62, 63, 65, 67, 70, 71, 72, 73, 75, 77, 79, 82, 83, 85, 89, 92, 93, 95, 97, 101, 102, 103, 105, 107, 109, 110, 112, 113, 115, 120

Offset

1,1

Comments

Numbers k such that A131929(k) > 0; complement of A050695 including 1.

All primes are terms.

Links

James C. McMahon, Table of n, a(n) for n = 1..10000

Example

55 is a term because 5 | 55.

Mathematica

Select[Range[2, 120], ContainsAny[Rest[FromDigits/@Subsets[IntegerDigits[#]]], First/@FactorInteger[#]]&] (* James C. McMahon, Mar 02 2025 *)

Crossrefs

Cf. A131929, A050695.

Sequence in context: A198096 A137923 A163753 * A384735 A230918 A001742

Adjacent sequences: A131927 A131928 A131929 * A131931 A131932 A131933

Keyword

nonn,base

Author

Reinhard Zumkeller, Jul 30 2007

Status

approved