A370920 Positive integers in whose ternary representation 2 occurs at least once, and every 2 is followed by 0.

6, 15, 18, 19, 33, 42, 45, 46, 54, 55, 57, 58, 60, 87, 96, 99, 100, 114, 123, 126, 127, 135, 136, 138, 139, 141, 162, 163, 165, 166, 168, 171, 172, 174, 175, 177, 180, 181, 249, 258, 261, 262, 276, 285, 288, 289, 297, 298, 300, 301, 303, 330, 339, 342, 343

Offset

1,1

Links

Table of n, a(n) for n=1..55.

Formula

The ternary representations of 6, 15, and 18 are 20, 120, and 200.

Mathematica

Map[#[[1]] &, Select[Map[{#, #[[1]] > 0 && #[[1]] == #[[2]] &[{Length[
StringCases[#, "2"]], Length[StringCases[#, "20"]]}] &[
IntegerString[#, 3]]} &, Range[500]], #[[2]] &]]   (* Peter J. C. Moses, Mar 05 2024 *)

Crossrefs

Cf. A007089, A074940.

Cf. A370916, A370917, A370918, A370919, A370921, A370922, A370923.

Sequence in context: A274549 A351175 A099535 * A302296 A070999 A128693

Adjacent sequences: A370917 A370918 A370919 * A370921 A370922 A370923

Keyword

nonn,base

Author

Clark Kimberling, Mar 16 2024

Status

approved