n - 5^k is a prime for all k > 0 and n > 5^k.

Terms

a(0) =7a(1) =8a(2) =10a(3) =12a(4) =16a(5) =18a(6) =22a(7) =24a(8) =28a(9) =36a(10) =42a(11) =48a(12) =66a(13) =72a(14) =78a(15) =84a(16) =108a(17) =114a(18) =132a(19) =156a(20) =162a(21) =198a(22) =204a(23) =276a(24) =282a(25) =288a(26) =318a(27) =336a(28) =492a(29) =504