Startorial numbers: product of initial digits of integers 1 through n.

Terms

a(0) =1a(1) =2a(2) =6a(3) =24a(4) =120a(5) =720a(6) =5040a(7) =40320a(8) =362880a(9) =362880a(10) =362880a(11) =362880a(12) =362880a(13) =362880a(14) =362880a(15) =362880a(16) =362880a(17) =362880a(18) =362880a(19) =725760a(20) =1451520a(21) =2903040a(22) =5806080a(23) =11612160a(24) =23224320a(25) =46448640a(26) =92897280a(27) =185794560a(28) =371589120a(29) =1114767360