Strong pseudoprimes to base 20.

Terms

a(0) =21a(1) =671a(2) =889a(3) =1891a(4) =2059a(5) =2761a(6) =5461a(7) =7999a(8) =13051a(9) =15311a(10) =16441a(11) =21667a(12) =25681a(13) =34861a(14) =37901a(15) =38989a(16) =42127a(17) =49771a(18) =50737a(19) =54811a(20) =64681a(21) =68251a(22) =78961a(23) =85591a(24) =88831a(25) =92509a(26) =93031a(27) =96049a(28) =97921a(29) =105001