A110443 Index k of the least colossally abundant number c=A004490(k) with sigma(c)/c >= n.

2, 5, 9, 14, 19, 27, 40, 56, 82, 119, 180, 275, 426, 673, 1072, 1728, 2807, 4596, 7558, 12497, 20741, 34544, 57704, 96638, 162204, 272802, 459637, 775678, 1310959, 2218651, 3759507, 6377858

Offset: 2

Author

T. D. Noe, Jul 20 2005

Keywords

• nonn
• more

Comments

For the numbers, instead of the indices, see A110442. The last term, a(33), yields a 48361012-digit number having 6375908 prime factors.

Examples

			a(4)=9 because the 9th colossally abundant number is c=55440 and sigma(c)/c = 4.18701 > 4, while the 8th colossally abundant number is c'=5040 and sigma(c')/c' = 3.838 < 4.
		

Crossrefs

Cf. A004490, A110442.

Extensions

Definition and example clarified by Jonathan Sondow, Dec 08 2011