Generate the prime sequence with primes labeled 1 mod 4 or 3 mod 4. Add count of primes to sequence if just 7 primes occur before interruption by a prime congruent to 1 mod 4.
EXAMPLE
a(5)=6 because 6 sets of 7 primes occur below 10^5, each run interrupted by a prime congruent to 1 mod 4.