a(n)= least number k > a(n-1) such that k*(2^p-1)*(k*(2^p-1)+1)-1 is prime, where p = A000043(n) = Mersenne exponents.
A200655
a(n)= least number k > a(n-1) such that k*(2^p-1)*(k*(2^p-1)+1)-1 is prime, where p = A000043(n) = Mersenne exponents.
Terms
- a(0) =1a(1) =3a(2) =5a(3) =7a(4) =8a(5) =19a(6) =20a(7) =23a(8) =96a(9) =190a(10) =312a(11) =400a(12) =434a(13) =852a(14) =980a(15) =1063a(16) =1208a(17) =3960a(18) =5464a(19) =6694a(20) =7178a(21) =13118a(22) =13680a(23) =18803a(24) =27445a(25) =28541a(26) =42031a(27) =73209a(28) =83873
External references
- oeis: A200655