Least k > 1 such that k^n is a twin rank (cf. A002822: 6*k^n +- 1 are twin primes).

Terms

a(0) =2a(1) =5a(2) =28a(3) =70a(4) =2a(5) =1820a(6) =110a(7) =1850a(8) =2520a(9) =220a(10) =2023a(11) =9415a(12) =647a(13) =2880a(14) =2562a(15) =3895a(16) =2a(17) =51240a(18) =525a(19) =3750a(20) =147a(21) =2350a(22) =355a(23) =4480a(24) =2588a(25) =3370a(26) =38157a(27) =1185a(28) =1473a(29) =12530