

A349467


Numbers k such that A349410(k) = 1.


1



1, 2, 3, 5, 6, 7, 8, 9, 11, 13, 17, 19, 21, 23, 25, 28, 29, 31, 32, 33, 36, 37, 39, 40, 41, 43, 47, 48, 49, 51, 53, 57, 59, 61, 67, 69, 70, 71, 73, 75, 79, 81, 83, 87, 89, 90, 93, 96, 97, 98, 101, 103, 107, 109, 110, 111, 113, 120, 121, 123, 126, 127, 128, 129, 130
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OFFSET

1,2


COMMENTS

Does this sequence have density 1/3? This sequence has infinitely many terms because every prime number is a term.
The numbers of terms not exceeding 10^k for k = 1, 2, ... are 8, 50, 396, 3566, 33943, 332042, 3297317, 32983277, ... Apparently this sequence has an asymptotic density of about 0.33.  Amiram Eldar, Nov 18 2021


LINKS

Table of n, a(n) for n=1..65.


MATHEMATICA

a[n_] := Module[{s = NestWhileList[n*DivisorSigma[0, #] &, 1, UnsameQ, All]}, Differences[Position[s, s[[1]]]][[1, 1]]]; Select[Range[130], a[#] == 1 &] (* Amiram Eldar, Nov 18 2021 *)


CROSSREFS

Cf. A349410.
Sequence in context: A346723 A346722 A007989 * A182942 A349095 A069224
Adjacent sequences: A349464 A349465 A349466 * A349468 A349469 A349470


KEYWORD

nonn


AUTHOR

Tejo Vrush, Nov 18 2021


STATUS

approved



