A380537 Numbers k such that k is a multiple of A351566(k), where A351566 is the radix prime of the second least significant nonzero digit in the primorial base expansion of n, or 1 if there is no such digit.

1, 2, 3, 4, 6, 9, 10, 12, 15, 18, 20, 21, 24, 25, 27, 30, 33, 39, 40, 42, 45, 50, 51, 55, 57, 60, 63, 69, 70, 75, 80, 81, 84, 85, 87, 90, 91, 93, 99, 100, 105, 110, 111, 115, 117, 120, 123, 126, 129, 130, 135, 140, 141, 145, 147, 150, 153, 154, 159, 160, 165, 168, 170, 171, 175, 177, 180, 182, 183, 189, 190, 195, 200

Offset

1,2

Comments

Numbers k such that k is a multiple of A119288(A276086(k)).

All terms of A060735 are present as the sequence gives the positions of 1's in A351566.

Note that the radix prime of the least significant nonzero digit in the primorial base expansion of n never divides n as it is A053669(n).

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Index entries for sequences related to primorial base.

Prog

(PARI) is_A380537 = A380536;

Crossrefs

Cf. A053669, A060735 (subsequence), A119288, A276086, A351566, A380536 (characteristic function), A380538 (complement).

Sequence in context: A249602 A119761 A144429 * A260194 A014851 A177919

Adjacent sequences: A380534 A380535 A380536 * A380538 A380539 A380540

Keyword

nonn

Author

Antti Karttunen, Feb 12 2025

Status

approved