a(n) = 1*2*3*4*5*6*7*8 + 9*10*11*12*13*14*15*16 + 17*18*19*20*21*22*23*24 + ... + (up to n).

Terms

a(0) =1a(1) =2a(2) =6a(3) =24a(4) =120a(5) =720a(6) =5040a(7) =40320a(8) =40329a(9) =40410a(10) =41310a(11) =52200a(12) =194760a(13) =2202480a(14) =32472720a(15) =518958720a(16) =518958737a(17) =518959026a(18) =518964534a(19) =519075000a(20) =521400600a(21) =572680080a(22) =1754550000a(23) =30173149440a(24) =30173149465a(25) =30173150090a(26) =30173166990a(27) =30173640840a(28) =30187400040