A sequence related to Catalan numbers A000108.

Terms

a(0) =1a(1) =-1a(2) =1a(3) =15a(4) =113a(5) =783a(6) =5361a(7) =36879a(8) =255985a(9) =1794063a(10) =12689393a(11) =90505231a(12) =650379249a(13) =4705157135a(14) =34244198385a(15) =250572963855