A134857 Numbers that can be written as (a^2-1)(b^2-1) in four or more distinct ways.

241920, 1048320, 10200960, 25724160, 37255680, 93139200, 123963840, 245044800, 588107520, 819786240, 1407893760, 1871251200, 3758169600, 5886558720, 8553283200, 10783342080, 13470367680, 19769460480, 30791819520, 40446806400

Offset: 1

Author

Herman Beeksma, Nov 13 2007

Keywords

• easy
• nonn

Comments

Subsequence of A134856. Contains A134858 as a subsequence.

Examples

			241920 = (4^2-1)(127^2-1) = (7^2-1)(71^2-1) = (9^2-1)(55^2-1) = (17^2-1)(29^2-1).
		

Links

• MathPages, Numbers Expressible As (a^2-1)(b^2-1).

Crossrefs

Cf. A134856, A134858.

Cf. A057535, A063066, A063067, A063068.