A092640 Number of consecutive prime runs of 2 primes congruent to 3 mod 4 below 10^n.
0, 5, 20, 101, 751, 5949, 49010, 418366, 3627049, 32067600, 287357618
Offset: 1
Examples
a(4)=101 because 101 pairs of primes occur below 10^4, each run interrupted by a prime congruent to 1 mod 4.
Formula
Generate the prime sequence with primes labeled 1 mod 4 or 3 mod 4. Add count of primes to sequence if just 2 primes occur before interruption by a prime congruent to 1 mod 4.
Extensions
a(9)-a(11) from Chai Wah Wu, Mar 18 2018