a(n) = n*(n+2)*(n+4)*(n+6)*(n+8)*(n+10)*(n+12)*(n+14).

Terms

a(0) =0a(1) =2027025a(2) =10321920a(3) =34459425a(4) =92897280a(5) =218243025a(6) =464486400a(7) =916620705a(8) =1703116800a(9) =3011753745a(10) =5109350400a(11) =8365982625a(12) =13284311040a(13) =20534684625a(14) =30996725760a(15) =45808142625a(16) =66421555200a(17) =94670161425a(18) =132843110400a(19) =183771489825a(20) =250925875200a(21) =338526428625a(22) =451666575360