a(n) = floor(product_{k=2..n} log(k)).

Terms

a(0) =0a(1) =0a(2) =1a(3) =1a(4) =3a(5) =5a(6) =12a(7) =27a(8) =62a(9) =149a(10) =371a(11) =952a(12) =2513a(13) =6807a(14) =18873a(15) =53472a(16) =154554a(17) =455076a(18) =1363287a(19) =4150560a(20) =12829558a(21) =40227005a(22) =127843589a(23) =411512640a(24) =1340747909a(25) =4418886387a(26) =14724633149a(27) =49582195801a(28) =168638834537a(29) =579103599979