a(n) is the least positive even number k such that among the first k prime numbers there are exactly k/2 prime numbers where the n-th least significant bit is one, or a(n) = -1 if no such k exists.
A308575
a(n) is the least positive even number k such that among the first k prime numbers there are exactly k/2 prime numbers where the n-th least significant bit is one, or a(n) = -1 if no such k exists.
Terms
- a(0) =2a(1) =2946a(2) =4a(3) =18a(4) =830a(5) =86a(6) =342a(7) =498a(8) =36002a(9) =2310a(10) =14660a(11) =3791908a(12) =138060a(13) =160110a(14) =998836a(15) =4345842a(16) =357341648a(17) =56717562a(18) =36609556a(19) =5972021576a(20) =2654687244a(21) =8237027666a(22) =22719286202a(24) =222365303318
External references
- oeis: A308575