a(n) = 6*binomial(n+1,5).

Terms

a(0) =6a(1) =36a(2) =126a(3) =336a(4) =756a(5) =1512a(6) =2772a(7) =4752a(8) =7722a(9) =12012a(10) =18018a(11) =26208a(12) =37128a(13) =51408a(14) =69768a(15) =93024a(16) =122094a(17) =158004a(18) =201894a(19) =255024a(20) =318780a(21) =394680a(22) =484380a(23) =589680a(24) =712530a(25) =855036a(26) =1019466a(27) =1208256a(28) =1424016a(29) =1669536