A290846 Numbers k such that sum of squares of divisors of k is a cube.

1, 4182, 4879, 122664360, 315870765, 4621320120, 5006430130, 20245909880, 220899101736, 239307360214, 812593845485

Offset: 1

Author

Altug Alkan, Aug 12 2017

Keywords

• nonn
• more

Comments

It is known that A006532 is an infinite sequence. Is this sequence infinite?

a(12) > 10^12. - Giovanni Resta, Aug 14 2017

Examples

			4879 is a term because 1^2 + 7^2 + 17^2 + 41^2 + 119^2 + 287^2 + 697^2 + 4879^2 = 290^3.
		

Links

• Giovanni Resta, A list of 3110 terms > 10^12

Crossrefs

Cf. A001157, A006532, A046655.

Programs

PARI

isok(n) = ispower(sigma(n, 2), 3);

Extensions

a(6)-a(11) from Giovanni Resta, Aug 14 2017