Number of primes == 3 (mod 10) less than 10^n.

A073506

Number of primes == 3 (mod 10) less than 10^n.

Terms

    a(0) =1a(1) =7a(2) =42a(3) =310a(4) =2402a(5) =19665a(6) =166230a(7) =1440474a(8) =12712499a(9) =113765625a(10) =1029509448a(11) =9401979904a(12) =86516427946

External references