a(n) = binomial(n+4,n)*binomial(n+8,n).

Terms

a(0) =1a(1) =45a(2) =675a(3) =5775a(4) =34650a(5) =162162a(6) =630630a(7) =2123550a(8) =6370650a(9) =17381650a(10) =43801758a(11) =103169430a(12) =229265400a(13) =484306200a(14) =978496200a(15) =1900457064a(16) =3563356995a(17) =6473226375a(18) =11428041625a(19) =19658764125a(20) =33026723730a(21) =54295634250a(22) =87501228750a(23) =138447123750a(24) =215362192500