327235662833domain: NAppears in sequencesNumerator of Sum[ (-1)^(k+1) * 1/2^Prime[k], {k,1,n} ].at n=12A122150Primes in A122150[n] = Numerator[ Sum[ (-1)^(k+1) * 1/2^Prime[k], {k,1,n} ] ].at n=2A122152