A020476 Numbers k such that the sum of divisors of k^3 is a cube.

1, 30154214043975990969, 76630991932799573643, 3590918978816938469301573291605, 68804810614900760202830061602802, 527113576787083306927808065765554478755087

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• more

Comments

WARNING: the listed terms are not proved to be in order. According to Basso (2017), it is not even proved that a(2) = 30154214043975990969. - Max Alekseyev, Mar 25 2023

Links

• Andrea Basso, Power values of the sigma function, Bachelor’s Project Mathematics, University of Gronigen, July 2017. See Appendix D p. 36.

Crossrefs

Cf. A000578, A175926.

Programs

PARI

isok(n) = ispower(sigma(n^3), 3); \\ Michel Marcus, Jul 19 2017