A382375 Lexicographically earliest sequence of distinct positive integers such that the number of prime factors counted with multiplicity of n and a(n) differ exactly by one.

2, 1, 4, 3, 6, 5, 9, 10, 7, 8, 14, 15, 21, 11, 12, 18, 22, 16, 25, 24, 13, 17, 26, 20, 19, 23, 33, 34, 35, 36, 38, 40, 27, 28, 29, 30, 39, 31, 37, 32, 46, 49, 51, 54, 55, 41, 57, 56, 42, 58, 43, 60, 62, 44, 45, 48, 47, 50, 65, 52, 69, 53, 74, 72, 59, 77, 82

Offset

1,1

Comments

A self-inverse permutation of the positive integers.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Rémy Sigrist, PARI program

Index entries for sequences that are permutations of the natural numbers

Example

The initial terms are:
  n   a(n)  A001222(n)  A001222(a(n))
  --  ----  ----------  -------------
   1     2           0              1
   2     1           1              0
   3     4           1              2
   4     3           2              1
   5     6           1              2
   6     5           2              1
   7     9           1              2
   8    10           3              2
   9     7           2              1
  10     8           2              3
  11    14           1              2
  12    15           3              2
  13    21           1              2
  14    11           2              1
  15    12           2              3

Prog

(PARI) \\ See Links section.

Crossrefs

Cf. A001222, A382374, A382377.

Sequence in context: A361740 A073672 A306230 * A071065 A389909 A359946

Adjacent sequences: A382372 A382373 A382374 * A382376 A382377 A382378

Keyword

nonn

Author

Rémy Sigrist, Mar 23 2025

Status

approved