7757430domain: NAppears in sequencesNumbers k such that 2*k+1, 4*k+1, 8*k+1, 16*k+1, 32*k+1, 64*k+1 and 128*k+1 are primes.at n=8A124415Numbers k such that 2*k+1, 4*k+1, 8*k+1, 16*k+1, 32*k+1, 64*k+1, 128*k+1 and 256*k+1 are primes.at n=0A124416a(n) = least k such that 2^i*k+1 is prime for 1<=i<=n.at n=7A124417