Binomial coefficients binomial(2*n-3,4).

Terms

a(0) =5a(1) =35a(2) =126a(3) =330a(4) =715a(5) =1365a(6) =2380a(7) =3876a(8) =5985a(9) =8855a(10) =12650a(11) =17550a(12) =23751a(13) =31465a(14) =40920a(15) =52360a(16) =66045a(17) =82251a(18) =101270a(19) =123410a(20) =148995a(21) =178365a(22) =211876a(23) =249900a(24) =292825a(25) =341055a(26) =395010a(27) =455126a(28) =521855a(29) =595665