Greatest k such that k-th prime < 3 times n-th prime.

Terms

a(0) =3a(1) =4a(2) =6a(3) =8a(4) =11a(5) =12a(6) =15a(7) =16a(8) =19a(9) =23a(10) =24a(11) =29a(12) =30a(13) =31a(14) =34a(15) =37a(16) =40a(17) =42a(18) =46a(19) =47a(20) =47a(21) =51a(22) =53a(23) =56a(24) =61a(25) =62a(26) =63a(27) =66a(28) =66a(29) =68