A281408 Lexicographically first sequence of distinct terms with the property that each triple of consecutive terms contains a term that divides the difference of the other two terms.

1, 2, 3, 5, 8, 13, 21, 4, 9, 17, 26, 43, 69, 112, 181, 23, 20, 63, 83, 10, 33, 53, 86, 11, 15, 37, 7, 6, 19, 25, 44, 94, 50, 22, 14, 36, 64, 28, 12, 16, 40, 24, 88, 32, 56, 120, 176, 296, 30, 38, 68, 106, 174, 34, 35, 103, 138, 241, 379, 46, 57, 149, 92, 333

Offset: 1

Author

Rémy Sigrist, Jan 21 2017

Keywords

• nonn

Examples

			The first terms, alongside the indexes of the terms that divides the difference of the other two terms within the n-th triple of consecutive terms, are:
   n  a(n)    Indexes
  --  ----    -------
   1     1    1, 2
   2     2    1, 2
   3     3    1, 2
   4     5    1, 2
   5     8    1, 2
   6    13    3
   7    21    2
   8     4    1
   9     9    1, 2
  10    17    1, 2
  11    26    1, 2
  12    43    1, 2
  13    69    1, 2
  14   112    3
  15   181    2
  16    23    2
  17    20    1, 2
  18    63    3
  19    83    2
  20    10    1
  21    33    1, 2
  22    53    3
  23    86    3
  24    11    1
  25    15    1
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, PARI program for A281408

Crossrefs

Cf. A278962, A281409.