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

Terms

a(0) =1a(1) =19a(2) =154a(3) =814a(4) =3289a(5) =11011a(6) =32032a(7) =83512a(8) =199342a(9) =442442a(10) =923780a(11) =1830764a(12) =3468374a(13) =6317234a(14) =11113784a(15) =18958808a(16) =31461815a(17) =50930165a(18) =80613390a(19) =125014890a(20) =190285095a(21) =284712285a(22) =419329560a(23) =608658960a(24) =871616460a(25) =1232604516a(26) =1722822024a(27) =2381824984