Binomial coefficient C(40,n).

Terms

a(0) =1a(1) =40a(2) =780a(3) =9880a(4) =91390a(5) =658008a(6) =3838380a(7) =18643560a(8) =76904685a(9) =273438880a(10) =847660528a(11) =2311801440a(12) =5586853480a(13) =12033222880a(14) =23206929840a(15) =40225345056a(16) =62852101650a(17) =88732378800a(18) =113380261800a(19) =131282408400a(20) =137846528820a(21) =131282408400a(22) =113380261800