a(n) = binomial(n+9,9)*2^n.

Terms

a(0) =1a(1) =20a(2) =220a(3) =1760a(4) =11440a(5) =64064a(6) =320320a(7) =1464320a(8) =6223360a(9) =24893440a(10) =94595072a(11) =343982080a(12) =1203937280a(13) =4074864640a(14) =13388840960a(15) =42844291072a(16) =133888409600a(17) =409541017600