a(n) = binomial coefficient C(n,41).

Terms

a(0) =1a(1) =42a(2) =903a(3) =13244a(4) =148995a(5) =1370754a(6) =10737573a(7) =73629072a(8) =450978066a(9) =2505433700a(10) =12777711870a(11) =60403728840a(12) =266783135710