A374482 Indices of records in A347381, where A347381 is the distance from n to the nearest common ancestor of n and sigma(n) in the Doudna-tree (A005940).

1, 3, 7, 17, 23, 29, 31, 47, 53, 71, 83, 89, 97, 107, 127, 139, 149, 167, 179, 191, 199, 233, 239, 241, 269, 293, 337, 349, 359, 373, 383, 419, 431, 449, 461, 479, 499, 569, 571, 577, 587, 599, 643, 647, 701, 719, 769, 809, 839, 857, 863, 881, 967, 971, 1013, 1039, 1049, 1091, 1151, 1187, 1217, 1223, 1231, 1249, 1279

Offset: 1

Author

Antti Karttunen, Jul 09 2024

Keywords

• nonn

Comments

Most likely, all terms are primes after the initial 1. Mersenne primes (A000668) are a subsequence.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..18144
• Index entries for sequences related to sigma(n)

Crossrefs

Cf. A000668 (subsequence), A005940, A347381, A374483 (record values).

Cf. also A374481.