a(n) = least k such that either 6*k*M(n)-1 or 6*k*M(n)+1 or both is prime, where M(i)= i-th Mersenne prime.
A145983
a(n) = least k such that either 6*k*M(n)-1 or 6*k*M(n)+1 or both is prime, where M(i)= i-th Mersenne prime.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =1a(4) =4a(5) =2a(6) =1a(7) =14a(8) =3a(9) =43a(10) =28a(11) =19a(12) =56a(13) =14a(14) =14a(15) =26a(16) =75a(17) =138a(18) =335a(19) =417a(20) =291a(21) =571a(22) =1508a(23) =7887a(24) =5893a(25) =5863a(26) =2877a(27) =9803a(28) =29975a(29) =7857
External references
- oeis: A145983