Lucky numbers with size of gaps equal to 6 (lower terms).

Terms

a(0) =15a(1) =25a(2) =37a(3) =43a(4) =87a(5) =93a(6) =99a(7) =105a(8) =135a(9) =163a(10) =195a(11) =205a(12) =261a(13) =267a(14) =297a(15) =321a(16) =361a(17) =385a(18) =393a(19) =409a(20) =415a(21) =421a(22) =477a(23) =489a(24) =511a(25) =529a(26) =553a(27) =645a(28) =673a(29) =679