a(0)=1; for n>0, a(n) = least k not included earlier such that k*a(n-1)-1 is a square.
1, 2, 5, 10, 17, 26, 37, 50, 65, 34, 13, 25, 41, 61, 85, 113, 145, 122, 101, 82, 293, 634
2 seqfan posts
Thu Feb 12 20:38:26 CET 2009 [seqfan] Re: sequence A069987