Let P(n) = primorial(n) = A002110(n); a(n) is the number of primes q < P(n) such that P(n) - q is also prime and q^2==1 (mod P(n)).

A336093

Let P(n) = primorial(n) = A002110(n); a(n) is the number of primes q < P(n) such that P(n) - q is also prime and q^2==1 (mod P(n)).

Terms

    a(0) =0a(1) =0a(2) =2a(3) =4a(4) =2a(5) =8a(6) =6a(7) =28a(8) =36a(9) =40a(10) =56a(11) =106a(12) =192a(13) =304a(14) =526a(15) =926a(16) =1644a(17) =2756a(18) =4944a(19) =8840a(20) =15958a(21) =28402a(22) =51102a(23) =92372

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