Least k such that k*7^n +/- 1 are twin primes.

Terms

a(0) =4a(1) =6a(2) =18a(3) =24a(4) =138a(5) =60a(6) =150a(7) =720a(8) =150a(9) =234a(10) =138a(11) =966a(12) =138a(13) =420a(14) =60a(15) =1584a(16) =420a(17) =60a(18) =1830a(19) =1134a(20) =162a(21) =1080a(22) =1482a(23) =684a(24) =240a(25) =10074a(26) =3378a(27) =3300a(28) =2742a(29) =984