a(n) = ceiling(sqrt(4*P_n)), where P_n is product of first n primes.

A173631

a(n) = ceiling(sqrt(4*P_n)), where P_n is product of first n primes.

Terms

    a(0) =2a(1) =3a(2) =5a(3) =11a(4) =29a(5) =97a(6) =347a(7) =1429a(8) =6229a(9) =29873a(10) =160869a(11) =895680a(12) =5448207a(13) =34885543a(14) =228759799a(15) =1568298164a(16) =11417382972a(17) =87698582661a(18) =684947826800

External references