Poupard's triangle: triangle of numbers arising in enumeration of binary trees.

Terms

a(0) =1a(1) =1a(2) =2a(3) =1a(4) =4a(5) =8a(6) =10a(7) =8a(8) =4a(9) =34a(10) =68a(11) =94a(12) =104a(13) =94a(14) =68a(15) =34a(16) =496a(17) =992a(18) =1420a(19) =1712a(20) =1816a(21) =1712a(22) =1420a(23) =992a(24) =496a(25) =11056a(26) =22112a(27) =32176a(28) =40256a(29) =45496