a(n) = 9*(n-2)*(5*n-13)*(5*n^2 - 19*n + 16)/2.

Terms

a(0) =0a(1) =36a(2) =1260a(3) =7452a(4) =25092a(5) =63360a(6) =134136a(7) =252000a(8) =434232a(9) =700812a(10) =1074420a(11) =1580436a(12) =2246940a(13) =3104712a(14) =4187232a(15) =5530680a(16) =7173936a(17) =9158580a(18) =11528892a(19) =14331852a(20) =17617140a(21) =21437136a(22) =25846920a(23) =30904272a(24) =36669672a(25) =43206300a(26) =50580036a(27) =58859460a(28) =68115852a(29) =78423192