a(n) = prime(2n) mod prime(n).

Terms

a(0) =1a(1) =1a(2) =3a(3) =5a(4) =7a(5) =11a(6) =9a(7) =15a(8) =15a(9) =13a(10) =17a(11) =15a(12) =19a(13) =21a(14) =19a(15) =25a(16) =21a(17) =29a(18) =29a(19) =31a(20) =35a(21) =35a(22) =33a(23) =45a(24) =35a(25) =37a(26) =45a(27) =49a(28) =53a(29) =55