A389219 Terms k of A228058 for which A048146(k)+A162296(k) >= 2*k, where A048146 is the sum of non-unitary divisors, and A162296 is the sum of divisors that have a square factor.

405, 1053, 1377, 2205, 2925, 3645, 3825, 5445, 5733, 6525, 7497, 7605, 8325, 9225, 9477, 11925, 12393, 12789, 13005, 13725, 14157, 16245, 16317, 16425, 18081, 18513, 19845, 20025, 21141, 21825, 22725, 23373, 23805, 24525, 25425, 25857, 26325, 26901, 26973, 28125, 29889, 30825, 31581, 32193, 32805, 33525, 33813

Offset

1,1

Comments

Terms k of A228058 for which A325974(k) >= k, or equally, A325978(k) <= 0.

Only 238 of the initial 10000 terms are in A386427 (i.e., are nondeficient).

If A228058 is a subsequence of A388986 as is conjectured (see A388986), then A386427 (nondeficient terms of A228058) is a subsequence of this sequence. - Antti Karttunen, Oct 05 2025

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Formula

{A228058(k) | A389218(k) <= 0}.

Prog

(PARI) is_A389219(n) = (is_A228058(n) && (A325978(n)<=0));
(PARI) is_A389219(k) = (is_A228058(k) && is_A389214(k));

Crossrefs

Intersection of A228058 and A389214.

Cf. A048146, A162296, A325978, A386427 (conjectured subsequence), A388986, A389218.

Sequence in context: A169904 A382547 A267893 * A151745 A204636 A224527

Adjacent sequences: A389216 A389217 A389218 * A389220 A389221 A389222

Keyword

nonn

Author

Antti Karttunen, Sep 25 2025

Status

approved