A331524 a(n) is the least positive k such that A006686(n) - k^8 is an eighth power.

1, 1, 1, 5, 3, 7, 2, 8, 3, 8, 9, 13, 4, 4, 17, 7, 17, 2, 8, 3, 5, 20, 7, 11, 17, 8, 23, 19, 10, 20, 3, 11, 17, 10, 22, 19, 14, 22, 17, 21, 25, 11, 13, 23, 27, 8, 32, 25, 33, 6, 25, 35, 7, 23, 31, 10, 37, 16, 18, 39, 5, 7, 42, 41, 30, 36, 5, 11, 8, 18, 30, 36

Offset

1,4

Links

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

Rémy Sigrist, PARI program for A331524

Example

The first terms, alongside A006686(n), are:
  n   a(n)  A006686(n)
  --  ----  -----------------------
   1     1           2 = 1^8 +  1^8
   2     1         257 = 1^8 +  2^8
   3     1       65537 = 1^8 +  4^8
   4     5     2070241 = 5^8 +  6^8
   5     3   100006561 = 3^8 + 10^8
   6     7   435746497 = 7^8 + 12^8
   7     2   815730977 = 2^8 + 13^8
   8     8   832507937 = 8^8 + 13^8
   9     3  1475795617 = 3^8 + 14^8
  10     8  2579667841 = 8^8 + 15^8

Prog

(PARI) See Links section.

Crossrefs

See A331435 for similar sequences.

Cf. A001016, A006686.

Sequence in context: A201752 A117126 A048997 * A096635 A021953 A171530

Adjacent sequences: A331521 A331522 A331523 * A331525 A331526 A331527

Keyword

nonn

Author

Rémy Sigrist, Jan 19 2020

Status

approved