a(n) = (n-1)*(n-2)^3 - A003878(n-3), with a(1) = a(2) = 0 and a(3) = 2.

Terms

a(0) =0a(1) =0a(2) =2a(3) =21a(4) =60a(5) =121a(6) =207a(7) =321a(8) =466a(9) =645a(10) =861a(11) =1117a(12) =1416a(13) =1761a(14) =2155a(15) =2601a(16) =3102a(17) =3661a(18) =4281a(19) =4965a(20) =5716a(21) =6537a(22) =7431a(23) =8401a(24) =9450a(25) =10581a(26) =11797a(27) =13101a(28) =14496a(29) =15985