cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A308293 Lexicographically earliest sequence of positive terms such that a(1) = 1, a(2) = 2, and for any n > 0, (abs(a(n+2)-a(n)), abs(a(n+2)-a(n+1))) is unique.

Original entry on oeis.org

1, 2, 1, 1, 1, 2, 3, 1, 1, 3, 1, 4, 1, 1, 4, 5, 1, 1, 5, 1, 2, 4, 6, 1, 1, 6, 1, 4, 6, 2, 1, 6, 2, 7, 1, 1, 7, 1, 8, 1, 1, 8, 3, 1, 7, 8, 1, 2, 5, 8, 1, 9, 1, 1, 9, 3, 1, 8, 9, 1, 3, 6, 10, 1, 1, 10, 1, 5, 8, 2, 10, 1, 8, 10, 1, 11, 1, 1, 11, 4, 1, 9, 10, 1
Offset: 1

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Author

Rémy Sigrist, May 19 2019

Keywords

Comments

This sequence shows chaotic behavior (see scatterplot in Links section).
This behavior is determined by the choice of the two leading terms.
The variant, say b, with b(1) = b(2) = 1, corresponds to the natural numbers interspersed with pairs of ones: 1,1,1, 2,1,1, 3,1,1, etc. (b(n) = abs(A157128(n))).

Examples

			The first terms, alongside (abs(a(n+2)-a(n)), abs(a(n+2)-a(n+1))), are:
  n   a(n)  (abs(a(n+2)-a(n)),abs(a(n+2)-a(n+1)))
  --  ----  -------------------------------------
   1     1  (0,1)
   2     2  (1,0)
   3     1  (0,0)
   4     1  (1,1)
   5     1  (2,1)
   6     2  (1,2)
   7     3  (2,0)
   8     1  (2,2)
   9     1  (0,2)
  10     3  (1,3)
  11     1  (0,3)
  12     4  (3,0)
  13     1  (3,3)
  14     1  (4,1)
  15     4  (3,4)
		

Crossrefs

See A080427 for a simpler variant.
Cf. A157128.

Programs

  • C
    See Links section.
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