A348031 - OEIS

A348031

Multiply-perfect numbers k that have a divisor d such that sigma(d)*d = k.

1, 6, 28, 120, 496, 672, 8128, 30240, 32760, 523776, 23569920, 33550336, 142990848, 1379454720, 8589869056, 66433720320, 137438691328, 153003540480, 403031236608, 14942123276641920, 275502900594021408, 2305843008139952128, 71065075104190073088, 154345556085770649600, 203820700083634254643200, 34384125938411324962897920

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Multiply-perfect numbers (A007691) that are present in A064987.

Note how the first three terms of A005820 are included here, while the next three are in A348032.

At least the even terms of A000396 are all present.

LINKS

Table of n, a(n) for n=1..26.

Index entries for sequences related to sigma(n)

CROSSREFS

Intersection of A007691 and A327165.