A tree-node counting triangle.

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =2a(5) =1a(6) =13a(7) =7a(8) =3a(9) =1a(10) =46a(11) =24a(12) =11a(13) =4a(14) =1a(15) =166a(16) =86a(17) =40a(18) =16a(19) =5a(20) =1a(21) =610a(22) =314a(23) =148a(24) =62a(25) =22a(26) =6a(27) =1a(28) =2269a(29) =1163