A387719 Odd numbers k such that the powerful part of the sum of divisors of k (A387726) is greater than or equal to k, and sigma(k) is not itself a powerful number.

350561925, 960362325, 1051884225, 3857173425, 4558583925

Offset

1,1

Comments

If any hypothetical odd perfect number is included in A386428 (intersection of A001694 and A228058), then it must be reside also in this sequence, and also in A386426.

Some of the terms are also found in A162284.

Links

Table of n, a(n) for n=1..5.

Crossrefs

Odd terms of A387729.

Cf. A000203, A001694, A057521, A228058, A386426, A386428.

Cf. also A162284.

Sequence in context: A015381 A257384 A186628 * A032757 A288273 A219271

Adjacent sequences: A387716 A387717 A387718 * A387720 A387721 A387722

Keyword

nonn,more

Author

Antti Karttunen, Sep 13 2025

Status

approved