a(n) = product of nonzero digits of n! (A000142).

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =8a(5) =2a(6) =14a(7) =20a(8) =24a(9) =2304a(10) =2304a(11) =11664a(12) =1512a(13) =2688a(14) =112896a(15) =508032a(16) =18579456a(17) =87091200a(18) =11854080a(19) =368640a(20) =6967296a(21) =22861440a(22) =542126592a(24) =40633270272a(25) =559872000a(26) =26873856000a(28) =178362777600