A387613 Numbers k such that A386482(k) and A386482(k+2) are coprime.

1, 3, 6, 9, 11, 12, 14, 18, 22, 24, 26, 29, 31, 32, 41, 42, 44, 45, 47, 49, 50, 52, 55, 57, 58, 68, 70, 71, 73, 74, 76, 77, 98, 101, 102, 104, 109, 113, 115, 119, 122, 123, 124, 126, 137, 138, 142, 144, 174, 179, 187, 189, 192, 193, 196, 203, 205, 207, 234

Offset

1,2

Comments

For k > 1, A386482(k) and A386482(k+1) share a prime factor, however A386482(k) and A386482(k+2) may not share a prime factor. The present sequence lists those indexes.

Links

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

Rémy Sigrist, PARI program

Example

The first terms, alongside the first terms of A386482, are:
  k   A386482(k)  A386482(k+2)  n   a(n)
  --  ----------  ------------  --  ----
   1           1             4   1     1
   2           2             6
   3           4             3   2     3
   4           6             9
   5           3            12
   6           9            10   3     6
   7          12             8
   8          10            14
   9           8             7   4     9
  10          14            21
  11           7            18   5    11
  12          21            16   6    12
  13          18            20
  14          16            15   7    14
  15          20             5

Prog

(PARI) \\ See Links section.

Crossrefs

Cf. A386482, A387087.

Sequence in context: A024795 A000408 A025321 * A153238 A343112 A230193

Adjacent sequences: A387610 A387611 A387612 * A387614 A387615 A387616

Keyword

nonn

Author

Rémy Sigrist, Sep 03 2025

Status

approved