Numbers n such that 4*10^n + R_n + 6 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
A102982
Numbers n such that 4*10^n + R_n + 6 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
Terms
- a(0) =1a(1) =4a(2) =84a(3) =165a(4) =274a(5) =513a(6) =3372a(7) =4177a(8) =4318a(9) =10579a(10) =17221a(11) =19672a(12) =20065a(13) =36646a(14) =40191a(15) =55359a(16) =86230
External references
- oeis: A102982