Least k such that k*10^n +/- 1 are twin primes.

Terms

a(0) =4a(1) =3a(2) =6a(3) =3a(4) =18a(5) =240a(6) =24a(7) =3a(8) =174a(9) =93a(10) =57a(11) =141a(12) =465a(13) =501a(14) =105a(15) =822a(16) =552a(17) =324a(18) =555a(19) =237a(20) =867a(21) =1488a(22) =543a(23) =2556a(24) =1050a(25) =105a(26) =51a(27) =429a(28) =1470a(29) =147