a(1) = 1; for n>1, a(n) = smallest number with all odd digits giving a prime in concatenation with the previous terms.

A069604

a(1) = 1; for n>1, a(n) = smallest number with all odd digits giving a prime in concatenation with the previous terms.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =11a(4) =1a(5) =3a(6) =3a(7) =53a(8) =13a(9) =39a(10) =9a(11) =3a(12) =399a(13) =11a(14) =9a(15) =133a(16) =3a(17) =11a(18) =51a(19) =111a(20) =13a(21) =53a(22) =31a(23) =3a(24) =173a(25) =1a(26) =317a(27) =519a(28) =579a(29) =1

External references