a(n) = t(n)*t(n+1)*t(n+2), where t() are the triangular numbers.

Terms

a(0) =0a(1) =18a(2) =180a(3) =900a(4) =3150a(5) =8820a(6) =21168a(7) =45360a(8) =89100a(9) =163350a(10) =283140a(11) =468468a(12) =745290a(13) =1146600a(14) =1713600a(15) =2496960a(16) =3558168a(17) =4970970a(18) =6822900a(19) =9216900a(20) =12273030a(21) =16130268a(22) =20948400a(23) =26910000a(24) =34222500a(25) =43120350a(26) =53867268a(27) =66758580a(28) =82123650a(29) =100328400