Primes of the form 2*k!!! + 1.A217648Primes of the form 2*k!!! + 1.Terms a(0) =3a(1) =3a(2) =5a(3) =7a(4) =37a(5) =3889a(6) =58321a(7) =8377601a(8) =22044961External referencesoeis: A217648