A Strange Sequence not in the OEoIS

[Jack Brennen]

David Harden wrote:
> 
> I think, though I haven't checked, that the fourth and fifth terms are, respectively,
 > 4801^2 - 1 = 23049600 and 19601^2 - 1 = 384199200.

8749^2 - 1 = 76545000 = 2^3 * 3^7 * 5^4 * 7.


An alternative way to express the sequence, at least how I thought of
it:  largest A such that A-1 and A+1 are both p-smooth, where p is the
nth prime.  Your sequence gives the (A-1)*(A+1) products.