%I #10 Apr 13 2024 23:25:13
%S 1111,6,205,427,1577,11639,1651,22499,2771,34571,253411,5129,60491,
%T 59701,8149,9517,307793,122491,13579,53237,168019,18103,202451,21667,
%U 169963,377753,27613,301337,88391,34633,368413,750523,418573,44287
%N a(n) = least semiprime with factors not previously used containing integers 2n and 2n+1 as substrings.
%e Sequence:....1111....6...205...427...1577....11639....1651..
%e Factors.:..101*11..2*3..41*5..61*7..83*19..103*113..127*13..
%e 2n, 2n+1:.....0,1..2,3...4,5...6,7....8,9....10,11...12,13..
%e n ......:.......0....1.....2.....3......4........5.......6..
%K base,easy,nonn
%O 0,1
%A _Jason Earls_, Aug 22 2003
%E More terms from _Ray Chandler_, Aug 31 2003