a(n) = (n+1)*(n+2)*(n+3)*(9n+4)/24.

Terms

a(0) =1a(1) =13a(2) =55a(3) =155a(4) =350a(5) =686a(6) =1218a(7) =2010a(8) =3135a(9) =4675a(10) =6721a(11) =9373a(12) =12740a(13) =16940a(14) =22100a(15) =28356a(16) =35853a(17) =44745a(18) =55195a(19) =67375a(20) =81466a(21) =97658a(22) =116150a(23) =137150a(24) =160875a(25) =187551a(26) =217413a(27) =250705a(28) =287680a(29) =328600