a(n) = 8*7*6*5*4*3*2*1 + 16*15*14*12*11*10*9 + ... + (up to the n-th term).

Terms

a(0) =8a(1) =56a(2) =336a(3) =1680a(4) =6720a(5) =20160a(6) =40320a(7) =40320a(8) =40336a(9) =40560a(10) =43680a(11) =84000a(12) =564480a(13) =5806080a(14) =57697920a(15) =518958720a(16) =518958744a(17) =518959272a(18) =518970864a(19) =519213744a(20) =524059200a(21) =615867840a(22) =2263322880a(23) =30173149440a(24) =30173149472a(25) =30173150432a(26) =30173179200a(27) =30174012480