a(n)=x is the smallest number such that gcd(prime(x)-1, x) = n.

Terms

a(0) =1a(1) =2a(2) =21a(3) =16a(4) =5a(5) =6a(6) =315a(7) =24a(8) =63a(9) =20a(10) =121a(11) =12a(12) =65a(13) =14a(14) =105a(15) =320a(16) =697a(17) =306a(18) =2185a(19) =60a(20) =399a(21) =286a(22) =299a(23) =216a(24) =575a(25) =156a(26) =513a(27) =644a(28) =1189a(29) =210