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

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =7a(6) =36a(7) =228a(8) =1647a(9) =13507a(10) =124268a(11) =1267542a(12) =14196477a(13) =173197024a(14) =2286200718a(15) =32464050199a(16) =493453563029