%I #5 Oct 22 2012 18:35:06
%S 49,7,84,159,5,31,95,143,40,35,29,9,21,156,431,53,231,230,6,329,82,30,
%T 223,45,181,275,206,454,1130,204,216,38,245,34,71,1080,561,338,181,
%U 119,238,525,333,95,431,855,367,430,554,50,1331,175,16,728,939,692,889
%N a(n) is the smallest positive integer k such that k^512 + 1 == 0 mod p(n) where p(n) are the n-th prime of the form 1 + 1024*b.
%t aa = {}; Do[p = Prime[n]; If[Mod[p, 1024] == 1, k = 1; While[ ! Mod[k^512 + 1, p] == 0, k++ ]; AppendTo[aa, k]], {n, 40000}]; aa
%K nonn
%O 1,1
%A _Michel Lagneau_, Oct 22 2012