Number of 6-ary rooted trees with n nodes and height exactly 3.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =2a(5) =4a(6) =6a(7) =10a(8) =14a(9) =19a(10) =24a(11) =31a(12) =37a(13) =46a(14) =52a(15) =61a(16) =68a(17) =76a(18) =81a(19) =88a(20) =90a(21) =94a(22) =94a(23) =94a(24) =90a(25) =88a(26) =81a(27) =76a(28) =68a(29) =61