Recursive triangle for calculating A186491.

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =0a(5) =3a(6) =0a(7) =14a(8) =0a(9) =15a(10) =28a(11) =0a(12) =132a(13) =0a(14) =105a(15) =0a(16) =5556a(17) =0a(18) =1500a(19) =0a(20) =945a(21) =1112a(22) =0a(23) =10668a(24) =0a(25) =1995a(26) =0a(27) =10395a(28) =0a(29) =43784