cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A348031 Multiply-perfect numbers k that have a divisor d such that sigma(d)*d = k.

Original entry on oeis.org

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
Offset: 1

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Author

Antti Karttunen, Sep 26 2021

Keywords

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

Crossrefs

Intersection of A007691 and A327165.
Cf. A000396, A005820, A064987, A348032 (complement in A007691), A348035 (subsequence).
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Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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