a(n) = (9*n + 11)*binomial(n+10, 10)/11.

Terms

a(0) =1a(1) =20a(2) =174a(3) =988a(4) =4277a(5) =15288a(6) =47320a(7) =130832a(8) =330174a(9) =772616a(10) =1696396a(11) =3527160a(12) =6995534a(13) =13312768a(14) =24426552a(15) =43385360a(16) =74847175a(17) =125777340a(18) =206390730a(19) =331405620a(20) =521690715a(21) =806403000a(22) =1225732560a(23) =1834391520a(24) =2706007980a(25) =3938612496a(26) =5661434520a(27) =8043259504