a(n) = round( Gamma(n+1/5)/Gamma(1/5) ).

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =2a(5) =7a(6) =37a(7) =229a(8) =1647a(9) =13507a(10) =124269a(11) =1267543a(12) =14196477a(13) =173197024a(14) =2286200718a(15) =32464050199a(16) =493453563029