G.f.: 1/(1 - 4*x + 5*x^2 - 100*x^3).

Terms

a(0) =1a(1) =4a(2) =11a(3) =124a(4) =841a(5) =3844a(6) =23571a(7) =159164a(8) =903201a(9) =5174084a(10) =32096731a(11) =192836604a(12) =1128271161a(13) =6758574724a(14) =40676603491a(15) =241740656444