Denominators of primes-only best approximates (POBAs) to Pi; see Comments.

Terms

a(0) =2a(1) =2a(2) =5a(3) =7a(4) =13a(5) =53a(6) =67a(7) =71a(8) =197a(9) =241a(10) =311a(11) =353a(12) =1427a(13) =1667a(14) =1723a(15) =3023a(16) =4591a(17) =5113a(18) =5749a(19) =9817a(20) =14563a(21) =15241a(22) =19309a(23) =43717a(24) =51853a(25) =56599a(26) =67447a(27) =199403a(28) =265381a(29) =12141887