Numbers n such that 10^(2n+1) + 21*10^n + 1 is prime.
A212129
Numbers n such that 10^(2n+1) + 21*10^n + 1 is prime.
Terms
- a(0) =2a(1) =3a(2) =11a(3) =12a(4) =15a(5) =42a(6) =311a(7) =314a(8) =579a(9) =1943a(10) =2262a(11) =5199a(12) =7329a(13) =12792
External references
- oeis: A212129