A110464 Oddly colossally abundant numbers.

3, 15, 45, 315, 3465, 45045, 135135, 675675, 11486475, 218243025, 5019589575, 145568097675, 4512611027925, 31588277195475, 94764831586425, 3506298768697725, 143758249516606725, 6181604729214089175

Offset: 1

Author

T. D. Noe, Jul 21 2005

Keywords

• nonn

Comments

The usual colossally abundant numbers (CANs) are defined in A004490; none of them is odd. Oddly CANs are defined similarly, except only odd primes are allowed in the factorization. It is conjectured that the ratio of consecutive oddly CANs is always a prime number. The sequence of those prime numbers is given in A110465.

Links

• Amiram Eldar, Table of n, a(n) for n = 1..65 (calculated from A110465)
• Lawrence C. Washington and Ambrose Yang, Analogues of the Robin-Lagarias criteria for the Riemann hypothesis, International Journal of Number Theory, Vol. 17, No. 4 (2021), pp. 843-870; arXiv preprint, arXiv:2008.04787 [math.NT], 2020.

Crossrefs

Cf. A004490, A110465.

Extensions

Name and comment clarified by Jonathan Sondow, Dec 08 2011