A374482 - OEIS

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

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OFFSET

1,2

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.

Sequence in context: A254680 A018411 A083989 * A277213 A152451 A097958

Adjacent sequences: A374479 A374480 A374481 * A374483 A374484 A374485

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jul 09 2024

STATUS

approved