A371112 Integers whose ternary representation consists of concatenated runs C(1)A(1)B(1)C(2)A(2)B(2)...C(k)A(k)B(k), where A(i) is a run of 1's, B(i) a run of 0's, and C(i) a run of 2's, for i = 1..k.

21, 63, 66, 75, 189, 198, 201, 225, 228, 237, 567, 588, 594, 603, 606, 675, 684, 687, 711, 714, 723, 1701, 1722, 1764, 1767, 1776, 1782, 1803, 1809, 1818, 1821, 2025, 2046, 2052, 2061, 2064, 2133, 2142, 2145, 2169, 2172, 2181

Offset

1,1

Comments

a(n) is a multiple of 3 for every n.

Links

Table of n, a(n) for n=1..42.

Mathematica

Map[#[[1]] &, Select[Map[{#, DeleteDuplicates[Partition[Map[#[[1]] &, Split[IntegerDigits[#, 3]]], UpTo[3]]] == {{2, 1, 0}}} &,
Range[3, 3600, 3]], #[[2]] &]] (* A371111 *)
m = Map[{#, IntegerString[#, 3]} &, %];
Map[Last, ToExpression[m]] (* this sequence *)
(* Peter J. C. Moses, Mar 06 2024 *)

Crossrefs

Cf. A007088, A371105, A371106, A371107, A371108, A371109, A371110, A371111.

Sequence in context: A081302 A058100 A219856 * A371052 A195106 A143203

Adjacent sequences: A371109 A371110 A371111 * A371113 A371114 A371115

Keyword

nonn,base

Author

Clark Kimberling, Apr 04 2024

Status

approved