Numbers k such that sigma(k) + tau(k) and sigma(k) - tau(k) are primes.

A065116

Numbers k such that sigma(k) + tau(k) and sigma(k) - tau(k) are primes.

Terms

    a(0) =8a(1) =162a(2) =512a(3) =32768a(4) =41472a(5) =3748322a(6) =5120000a(7) =6837602a(8) =8000000a(9) =35701250a(10) =75031250a(11) =78125000a(12) =91125000a(13) =907039232a(14) =10660336128a(15) =11911961250a(16) =21234895362a(17) =41265473762a(18) =55965865922a(19) =209642370242a(20) =835707290112

External references