a(n) = floor(Product_{k=1..n} log(prime(k))).

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =5a(5) =14a(6) =41a(7) =122a(8) =383a(9) =1291a(10) =4436a(11) =16019a(12) =59491a(13) =223758a(14) =861503a(15) =3420420a(16) =13946890a(17) =57333909a(18) =241071466a(19) =1027610488a(20) =4408921123a(21) =19264550934a(22) =85126979960a(23) =382104058297