a(1)=1; otherwise, find the first digit from the left in a(n-1) which is 1, 3, 7 or 9. Omitting the digits before this one, we reverse the remaining digits, obtaining s, say. Then a(n) is the smallest prime which ends with s and has not already appeared.
A249974
a(1)=1; otherwise, find the first digit from the left in a(n-1) which is 1, 3, 7 or 9. Omitting the digits before this one, we reverse the remaining digits, obtaining s, say. Then a(n) is the smallest prime which ends with s and has not already appeared.
Terms
- a(0) =1a(1) =11a(2) =211a(3) =311a(4) =2113a(5) =2311a(6) =5113a(7) =6311a(8) =6113a(9) =8311a(10) =11113a(11) =131111a(12) =3111131a(13) =21311113a(14) =63111131a(15) =31311113a(16) =31111313a(17) =531311113a(18) =1131111313a(19) =273131111311a(20) =311311113137
External references
- oeis: A249974