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.

A360960 Inverse permutation to A360959.

Original entry on oeis.org

0, 1, 3, 2, 7, 4, 6, 5, 15, 8, 14, 9, 13, 10, 12, 11, 31, 23, 30, 24, 29, 25, 28, 26, 27, 21, 22, 16, 20, 17, 19, 18, 35, 32, 34, 33, 63, 51, 62, 52, 61, 53, 60, 54, 59, 55, 58, 56, 57, 36, 50, 37, 49, 38, 48, 39, 47, 40, 46, 41, 45, 42, 44, 43, 127, 111, 126
Offset: 0

Views

Author

Rémy Sigrist, Feb 27 2023

Keywords

Examples

			A360959(42) = 61, so a(61) = 42.
		

Crossrefs

Cf. A360959.

Programs

  • PARI
    See Links section.

Formula

a(n) < 2^k for any n < 2^k.

A360982 Order the nonnegative integers by increasing binary length of values, then by decreasing binary length of values squared, then by increasing binary length of values cubed, etc.

Original entry on oeis.org

0, 1, 3, 2, 6, 7, 5, 4, 12, 15, 14, 13, 10, 9, 8, 11, 23, 24, 25, 27, 30, 31, 29, 28, 26, 20, 18, 17, 16, 19, 21, 22, 46, 47, 48, 50, 49, 54, 55, 59, 60, 61, 63, 62, 58, 56, 57, 52, 51, 53, 39, 40, 36, 35, 34, 32, 33, 37, 38, 42, 41, 43, 44, 45, 91, 92, 93, 94
Offset: 0

Views

Author

Rémy Sigrist, Feb 27 2023

Keywords

Comments

We ignore leading zeros (and 0 is assumed to have binary length 0).
This sequence is a permutation of the nonnegative integers with inverse A360983.
The order of appearance of two distinct integers, say x and y with x > y, depends on the parity of A360963(x, y): even implies x appears before y, odd implies x appears after y.

Examples

			The first terms, alongside the binary length of their first powers, are:
  n   a(n)  w1  w2  w3  w4  w5  w6
  --  ----  --  --  --  --  --  --
   0     0   0
   1     1   1
   2     3   2   4
   3     2   2   3
   4     6   3   6   8
   5     7   3   6   9
   6     5   3   5   7  10
   7     4   3   5   7   9
   8    12   4   8  11
   9    15   4   8  12  16  20  24
  10    14   4   8  12  16  20  23
  11    13   4   8  12  15
  12    10   4   7  10  14
  13     9   4   7  10  13  16  20
  14     8   4   7  10  13  16  19
  15    11   4   7  11
		

Crossrefs

See A360959 for a similar sequence.
Cf. A360963, A360983 (inverse).

Programs

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