Number of (w,x,y,z) with all terms in {1,...,n} and 2*w*x<3*y*z.

Terms

a(0) =0a(1) =1a(2) =11a(3) =50a(4) =160a(5) =387a(6) =792a(7) =1480a(8) =2511a(9) =4001a(10) =6104a(11) =8943a(12) =12623a(13) =17396a(14) =23374a(15) =30765a(16) =39803a(17) =50707a(18) =63656a(19) =79050a(20) =96985a(21) =117795a(22) =141871a(23) =169444a(24) =200754a(25) =236327a(26) =276397a(27) =321322a(28) =371547a(29) =427471