A069179 Least number X such that for each k in (0 to n-1), 2^k*X-1 and 2^k*X+1 are primes. That is, there are N twin primes, each the "double" of the previous.
4, 6, 211050, 253680, 41887255410, 73768891456260
Offset: 1
Keywords
Examples
a(3) = 211050 because 1*a(3)-1, 1*a(3)+1, 2*a(3)-1, 2*a(3)+1, 4*a(3)-1 and 4*a(3)+1 are all prime.
Crossrefs
Equals A068635 + 1.
Comments