Numbers k such that 10^k == -1 (mod k-1).

Terms

a(0) =2a(1) =102a(2) =41310a(3) =102690a(4) =309162a(5) =315150a(6) =1000002a(7) =2488530a(8) =4564350a(9) =12679002a(10) =17166870a(11) =28855610a(12) =35049930a(13) =38982870a(14) =42176490a(15) =43232070a(16) =53288510a(17) =64253070a(18) =104439090a(19) =126446850a(20) =130659210a(21) =144379602a(22) =208313490a(23) =252852390a(24) =284335410a(25) =284397750a(26) =337122750a(27) =379257930a(28) =385659630