a(n) = 10*(n+1)*binomial(n+3,5)/3.

Terms

a(0) =10a(1) =80a(2) =350a(3) =1120a(4) =2940a(5) =6720a(6) =13860a(7) =26400a(8) =47190a(9) =80080a(10) =130130a(11) =203840a(12) =309400a(13) =456960a(14) =658920a(15) =930240a(16) =1288770a(17) =1755600a(18) =2355430a(19) =3116960a(20) =4073300a(21) =5262400a(22) =6727500a(23) =8517600a(24) =10687950a(25) =13300560a(26) =16424730a(27) =20137600