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

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =2a(5) =8a(6) =18a(7) =45a(8) =84a(9) =144a(10) =240a(11) =375a(12) =540a(13) =792a(14) =1092a(15) =1470a(16) =1960a(17) =2560a(18) =3240a(19) =4131a(20) =5130a(21) =6300a(22) =7700a(23) =9317a(24) =11088a(25) =13248a(26) =15600a(27) =18252a(28) =21294a(29) =24696