a(n) = n!/(1!*2!*3!*...*k!) where k is the largest integer such that 1!*2!*3!*...*k! divides n!.

A074199

a(n) = n!/(1!*2!*3!*...*k!) where k is the largest integer such that 1!*2!*3!*...*k! divides n!.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =2a(4) =10a(5) =60a(6) =420a(7) =140a(8) =1260a(9) =105a(10) =1155a(11) =13860a(12) =180180a(13) =2522520a(14) =37837800a(15) =840840a(16) =14294280a(17) =51051a(18) =969969a(19) =19399380a(20) =407386980a(21) =8962513560a(22) =206137811880a(25) =79755701025

External references