A317180 a(n) is the least positive multiple of n that contains at least one digit 1 in its decimal representation.

1, 10, 12, 12, 10, 12, 14, 16, 18, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 100, 21, 110, 115, 120, 100, 104, 81, 112, 116, 120, 31, 128, 132, 102, 105, 108, 111, 114, 117, 120, 41, 126, 129, 132, 135, 138, 141, 144, 147, 100, 51, 104, 106, 108, 110, 112, 114

Offset

1,2

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Formula

a(n) = n * A317173(n).

a(n) <= A187285(n).

Example

The multiples of 3 are: 3, 6, 9, 12, 15, etc.; 12 is the first one containing the digit 1, hence a(3) = 12.

Mathematica

on1[n_]:=Module[{k=1}, While[DigitCount[k*n, 10, 1]<1, k++]; k*n]; Array[on1, 60] (* Harvey P. Dale, Apr 09 2022 *)

Prog

(PARI) a(n) = forstep (m=n, oo, n, if (setsearch(Set(digits(m)), 1), return (m)))

Crossrefs

Cf. A011531, A187285, A317173.

Sequence in context: A303151 A103618 A308781 * A187285 A098732 A301860

Adjacent sequences: A317177 A317178 A317179 * A317181 A317182 A317183

Keyword

nonn,base

Author

Rémy Sigrist, Jul 23 2018

Extensions

Definition clarified by Harvey P. Dale, Apr 09 2022

Status

approved