A063067 Numbers expressible as (a^2-1)(b^2-1) in at least 2 distinct ways (b>=a>1).

360, 504, 2304, 2520, 2880, 3465, 5040, 5400, 7920, 9360, 12285, 12600, 12672, 13440, 14400, 17325, 20160, 23040, 27720, 28224, 29400, 30600, 32760, 35640, 38080, 40320, 42840, 47880, 48384, 49920, 51480, 57960, 60480, 63360, 72072

Offset: 1

Author

Henry Bottomley, Jul 08 2001

Keywords

• nonn

Examples

			360 is on the list since 360 = (2^2-1)(11^2-1) = (4^2-1)(5^2-1).
		

Links

• Donovan Johnson, Table of n, a(n) for n = 1..1000
• K. S. Brown, Numbers Expressible as (a^2-1)(b^2-1)

Crossrefs

Cf. A057535, A063066, A063068.