A380535 Numbers such that the least significant nonzero digit in their primorial base representation (A049345) is greater than 1.

4, 10, 12, 16, 18, 22, 24, 28, 34, 40, 42, 46, 48, 52, 54, 58, 60, 64, 70, 72, 76, 78, 82, 84, 88, 90, 94, 100, 102, 106, 108, 112, 114, 118, 120, 124, 130, 132, 136, 138, 142, 144, 148, 150, 154, 160, 162, 166, 168, 172, 174, 178, 180, 184, 190, 192, 196, 198, 202, 204, 208, 214, 220, 222, 226, 228, 232, 234, 238, 244, 250

Offset

1,1

Comments

Equally, numbers k such that A327860(k) [equally, A329029(k)] is a multiple of A053669(k), where A327860 is the arithmetic derivative of the primorial base exp-function, and A053669(k) gives the least prime not dividing k. See comments in A329029.

Links

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

Index entries for sequences related to primorial base.

Formula

{k such that A276088(k) > 1}.

Example

   n, A049345(n), A276088(n)
  ---------------------------------------------
   4       20       2, thus 4 is present,
  10      120       2, thus 10 is present,
  11      121       1, thus 11 is not present,
  12      200       2, thus 12 is present,
  14      210       1, thus 14 is not present,
  16      220       2, thus 16 is present,
  18      300       3, thus 18 is present.

Prog

(PARI) is_A380535 = A380534;

Crossrefs

Cf. A049345, A053669, A276088, A327860, A329029, A380527, A380534 (characteristic function).

Cf. also A342018.

Sequence in context: A239055 A295129 A287338 * A077654 A095275 A366530

Adjacent sequences: A380532 A380533 A380534 * A380536 A380537 A380538

Keyword

nonn,base,easy,new

Author

Antti Karttunen, Feb 11 2025

Status

approved