Numbers k such that R_k + 70 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
A256761
Numbers k such that R_k + 70 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) =9a(5) =10a(6) =16a(7) =124a(8) =243a(9) =303a(10) =459a(11) =471a(12) =520a(13) =591a(14) =1726a(15) =2971a(16) =5560a(17) =5757a(18) =13222
External references
- oeis: A256761