A376676 a(n) is the unique k such that the run lengths transform of A376637(n) equals A376637(k).

1, 1, 2, 3, 3, 2, 5, 4, 4, 5, 9, 6, 7, 7, 6, 9, 10, 11, 8, 13, 13, 8, 11, 10, 15, 12, 12, 15, 14, 21, 16, 17, 19, 18, 18, 19, 17, 16, 21, 14, 23, 22, 24, 20, 20, 24, 22, 23, 27, 28, 25, 26, 26, 25, 28, 27, 38, 30, 29, 34, 33, 32, 32, 33, 34, 29, 30, 38, 37, 36

Offset: 1

Author

Rémy Sigrist, Oct 01 2024

Keywords

• nonn
• base

Comments

Every positive integer appears twice in this sequence.

Examples

			The first terms, alongside the corresponding terms of A376637, are:
  n   a(n)  A376637(n)  A376637(a(n))
  --  ----  ----------  -------------
   1     1           1              1
   2     1           2              1
   3     2          11              2
   4     3          12             11
   5     3          21             11
   6     2          22              2
   7     5         112             21
   8     4         122             12
   9     4         211             12
  10     5         221             21
  11     9        1121            211
  12     6        1122             22
  13     7        1211            112
  14     7        2122            112
  15     6        2211             22
  16     9        2212            211
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10048
• Rémy Sigrist, PARI program

Crossrefs

Cf. A351653, A376637, A376698, A376733.

Programs

PARI

\\ See Links section.

Formula

A376637(a(n)) = A351653(A376637(n)).