a(n) = floor( Gamma(n + 3/5)/Gamma(3/5) ).

Terms

a(0) =1a(1) =0a(2) =0a(3) =2a(4) =8a(5) =41a(6) =231a(7) =1527a(8) =11610a(9) =99850a(10) =958561a(11) =10160755a(12) =117864768a(13) =1485096081a(14) =20197306708a(15) =294880677941