a(n) is the number of primes p less than or equal to 10^n such that p+2 has only prime factors congruent to -1 modulo 4.
A369111
a(n) is the number of primes p less than or equal to 10^n such that p+2 has only prime factors congruent to -1 modulo 4.
Terms
- a(0) =2a(1) =12a(2) =65a(3) =388a(4) =2708a(5) =19969a(6) =155369a(7) =1250182a(8) =10345920a(9) =87545946a(10) =753285178a(11) =6571105993
External references
- oeis: A369111