1,1

Note that each term is a multiple of the preceding term (at least up to a(5)).

K. S. Brown, Numbers Expressible as (a^2-1)(b^2-1)

K. S. Brown, MathPages Most Wanted List Problem #14

a(4)=241920 since 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)

Cf. A057535, A063066, A063067.

Sequence in context: A055601 A012812 A119756 this_sequence A130558 A132593 A162133

Adjacent sequences: A063065 A063066 A063067 this_sequence A063069 A063070 A063071

more,nonn

Henry Bottomley (se16(AT)btinternet.com), Jul 08 2001