Numbers k such that R_k + 40 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
A256725
Numbers k such that R_k + 40 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
Terms
- a(0) =1a(1) =3a(2) =4a(3) =7a(4) =60a(5) =394a(6) =552a(7) =1164a(8) =1494a(9) =5398a(10) =7899a(11) =11254a(12) =13224a(13) =77637a(14) =118324a(15) =120574a(16) =142425a(17) =142699a(18) =157792a(19) =188164
External references
- oeis: A256725