Numbers k such that 10^k + 6*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
A102941
Numbers k such that 10^k + 6*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
Terms
- a(0) =1a(1) =3a(2) =5a(3) =7a(4) =11a(5) =12a(6) =28a(7) =36a(8) =384a(9) =629a(10) =720a(11) =1398a(12) =2002a(13) =2622a(14) =6457a(15) =19305a(16) =38508a(17) =46455a(18) =95976a(19) =102107a(20) =148505a(21) =189693
External references
- oeis: A102941