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.

Showing 1-2 of 2 results.

A369282 Inverse permutation to A369281.

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 6, 9, 10, 12, 8, 14, 11, 17, 16, 19, 18, 23, 13, 25, 15, 21, 20, 27, 22, 29, 30, 33, 32, 38, 24, 31, 34, 40, 26, 44, 28, 35, 36, 42, 37, 46, 47, 48, 49, 57, 39, 59, 41, 50, 51, 52, 53, 61, 43, 54, 55, 63, 45, 65, 56, 67, 68, 69, 70, 80, 58
Offset: 1

Views

Author

Rémy Sigrist, Jan 18 2024

Keywords

Examples

			A369281(42) = 40, so a(40) = 42.

Links

Crossrefs

Cf. A369281.

Programs

  • PARI
    See Links section.

A369293 Lexicographically earliest sequence of distinct positive integers such that a(1) = 1, a(2) = 2, and for any n > 1, A091255(a(n), a(n+1)) <> 1.

Original entry on oeis.org

1, 2, 4, 6, 3, 5, 9, 7, 14, 8, 10, 12, 15, 17, 18, 16, 20, 22, 11, 29, 23, 13, 26, 24, 27, 21, 28, 30, 32, 34, 33, 31, 62, 36, 35, 42, 38, 19, 53, 39, 40, 43, 25, 50, 44, 46, 45, 48, 51, 54, 49, 56, 52, 57, 58, 60, 63, 65, 66, 64, 68, 70, 72, 71, 61, 122, 74
Offset: 1

Views

Author

Rémy Sigrist, Jan 18 2024

Keywords

Comments

In other words, the polynomials over GF(2) whose coefficients are encoded in the binary expansions of two consecutive terms (beyond the initial term) are not coprime.
This sequence is a variant of the EKG sequence (A064413).
Is this a permutation of the positive integers?

Examples

			The first terms, alongside A091255(a(n), a(n+1)), are:
  n   a(n)  A091255(a(n), a(n+1))
  --  ----  ---------------------
   1     1                      1
   2     2                      2
   3     4                      2
   4     6                      3
   5     3                      3
   6     5                      3
   7     9                      7
   8     7                      7
   9    14                      2
  10     8                      2

Links

Crossrefs

See A369281 and A369294 for similar sequences.
Cf. A064413, A091255, A369302.

Programs

  • PARI
    See Links section.
Showing 1-2 of 2 results.

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