Primes which set a new record for length of Pratt certificate.

Terms

a(0) =2a(1) =3a(2) =7a(3) =23a(4) =43a(5) =139a(6) =283a(7) =659a(8) =1319a(9) =5179a(10) =9227a(11) =23159a(12) =55399a(13) =148439a(14) =366683a(15) =793439a(16) =1953839a(17) =4875119a(18) =9750239a(19) =27353747a(20) =71815607a(21) =192287243a(22) =430893643