An inverse Catalan transform of J(3n)/J(3).

Terms

a(0) =0a(1) =1a(2) =6a(3) =43a(4) =291a(5) =1992a(6) =13595a(7) =92845a(8) =633966a(9) =4329023a(10) =29560367a(11) =201850896a(12) =1378323999a(13) =9411785201a(14) =64267689006a(15) =438847231427