Numbers k such that 3*R_k + 10 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
A256570
Numbers k such that 3*R_k + 10 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =5a(4) =11a(5) =16a(6) =22a(7) =24a(8) =110a(9) =232a(10) =557a(11) =566a(12) =888a(13) =1946a(14) =2610a(15) =3302a(16) =10214a(17) =41756a(18) =89160a(19) =120782
External references
- oeis: A256570