A371109 Ternary numbers that are concatenated runs C(1)B(1)A(1)C(2)B(2)A(2)...C(k)B(k)A(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.

201, 2001, 2011, 2201, 20001, 20011, 20111, 22001, 22011, 22201, 200001, 200011, 200111, 201111, 201201, 220001, 220011, 220111, 222001, 222011, 222201, 2000001, 2000011, 2000111, 2001111, 2001201, 2011111, 2011201, 2012001, 2012011, 2012201, 2200001

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Mathematica

Map[#[[1]] &, Select[Map[{#, DeleteDuplicates[Partition[Map[#[[1]] &, Split[IntegerDigits[#, 3]]], UpTo[3]]] == {{2, 0, 1}}} &,
Range[1, 3600, 3]], #[[2]] &]] (* this sequence *)
m = Map[{#, IntegerString[#, 3]} &, %];
Map[Last, ToExpression[m]] (* A371110 *)
(*Peter J. C. Moses, Mar 06 2024 *)

Crossrefs

Cf. A007088, A371105, A371106, A371107, A371108, A371110, A371111, A371112.

Sequence in context: A183350 A226566 A061697 * A371057 A305724 A167070

Adjacent sequences: A371106 A371107 A371108 * A371110 A371111 A371112

Keyword

nonn,base

Author

Clark Kimberling, Mar 31 2024

Status

approved