Binomial coefficient C(4n,n-7).

Terms

a(0) =1a(1) =32a(2) =630a(3) =9880a(4) =135751a(5) =1712304a(6) =20358520a(7) =231917400a(8) =2558620845a(9) =27540584512a(10) =290752384208