Numbers k such that 10^k + 4*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
A102934
Numbers k such that 10^k + 4*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
Terms
- a(0) =1a(1) =3a(2) =4a(3) =6a(4) =9a(5) =22a(6) =28a(7) =34a(8) =37a(9) =61a(10) =82a(11) =274a(12) =276a(13) =735a(14) =1443a(15) =2215a(16) =2968a(17) =3301a(18) =3883a(19) =3991a(20) =5152a(21) =8032a(22) =8946a(23) =46642a(24) =57691
External references
- oeis: A102934