a(n) is the minimal k such that 5^n +/- k are primes.

Terms

a(0) =2a(1) =6a(2) =12a(3) =6a(4) =42a(5) =18a(6) =66a(7) =126a(8) =144a(9) =762a(10) =78a(11) =318a(12) =1026a(13) =84a(14) =264a(15) =354a(16) =288a(17) =102a(18) =1242a(19) =162a(20) =168a(21) =318a(22) =2058a(23) =234a(24) =2352a(25) =252a(26) =2532a(27) =42a(28) =342a(29) =102