Maximilian is right. The sequence goes %S A037083 1,2,4,5,6,7,9,10,11,17,24,29,39,40,57,58,59,91,155,175,245,359,372, %T A037083 597,864,977,1077,1327,2076,4798 BTW, p-1 primality proofs are easy for such numbers. -- Don Reble djr at nk.ca -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.