Binomial coefficient C(4n,n-3).

Terms

a(0) =1a(1) =16a(2) =190a(3) =2024a(4) =20475a(5) =201376a(6) =1947792a(7) =18643560a(8) =177232627a(9) =1677106640a(10) =15820024220a(11) =148902215280