A335043 Lexicographically earliest sequence of distinct positive integers such that for any n > 0, the decimal representations of a(2*n-1) and of a(2*n+1) appear as substrings in the decimal representation of a(2*n).

1, 12, 2, 23, 3, 34, 4, 45, 5, 56, 6, 67, 7, 78, 8, 89, 9, 109, 10, 110, 11, 113, 13, 130, 30, 330, 33, 331, 31, 314, 14, 140, 40, 240, 24, 224, 22, 220, 20, 320, 32, 321, 21, 215, 15, 150, 50, 250, 25, 251, 51, 351, 35, 352, 52, 526, 26, 260, 60, 160, 16, 161

Offset: 1

Author

Rémy Sigrist, Jun 01 2020

Keywords

• nonn
• base

Comments

This sequence has similarities with A281978; here we look for substrings, there for divisors.

This sequence has similarities with A262323: in both sequences, consecutive terms overlap.

Examples

			The first terms are:
  n   a(n)
  --  ------
   1  1
   2  12
   3   2
   4   23
   5    3
   6    34
   7     4
   8     45
   9      5
  10      56
  11       6
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10001
• Rémy Sigrist, Colored logarithmic scatterplot of the first 10001 terms (where the color denotes the parity of n)
• Rémy Sigrist, PARI program for A335043

Crossrefs

Cf. A262323, A281978.

Programs

PARI

See Links section.