a(n) = A072181(n) - p, where p is the largest prime < A072181(n) - 1.

Terms

a(0) =3a(1) =5a(2) =7a(3) =7a(4) =11a(5) =11a(6) =11a(7) =11a(8) =13a(9) =23a(10) =17a(11) =17a(12) =17a(13) =41a(14) =191a(15) =47a(16) =31a(17) =53a(18) =53a(19) =53a(20) =31a(21) =179a(22) =61a(23) =61a(24) =337a(25) =131a(26) =523a(27) =523a(28) =419a(29) =223