a(n) = binomial(n+5,4) - 1.

Terms

a(0) =4a(1) =14a(2) =34a(3) =69a(4) =125a(5) =209a(6) =329a(7) =494a(8) =714a(9) =1000a(10) =1364a(11) =1819a(12) =2379a(13) =3059a(14) =3875a(15) =4844a(16) =5984a(17) =7314a(18) =8854a(19) =10625a(20) =12649a(21) =14949a(22) =17549a(23) =20474a(24) =23750a(25) =27404a(26) =31464a(27) =35959a(28) =40919a(29) =46375