a(n) = n*(n-1)^2*(n-2).

Terms

a(0) =0a(1) =12a(2) =72a(3) =240a(4) =600a(5) =1260a(6) =2352a(7) =4032a(8) =6480a(9) =9900a(10) =14520a(11) =20592a(12) =28392a(13) =38220a(14) =50400a(15) =65280a(16) =83232a(17) =104652a(18) =129960a(19) =159600a(20) =194040a(21) =233772a(22) =279312a(23) =331200a(24) =390000a(25) =456300a(26) =530712a(27) =613872a(28) =706440a(29) =809100