a(1) = 1, a(n) = smallest prime number not already used such that concatenation of a(k) and a(n) is composite for all k = 1 to n-1.

A075612

a(1) = 1, a(n) = smallest prime number not already used such that concatenation of a(k) and a(n) is composite for all k = 1 to n-1.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =17a(4) =19a(5) =43a(6) =61a(7) =127a(8) =149a(9) =199a(10) =263a(11) =349a(12) =353a(13) =461a(14) =587a(15) =769a(16) =809a(17) =883a(18) =1009a(19) =1303a(20) =1619a(21) =2179a(22) =2207a(23) =2467a(24) =2591a(25) =2593a(26) =2909a(27) =3019a(28) =3517a(29) =3821

External references