Number of ordered trees with n edges such that non-leaf vertices at even levels have outdegree 1 and those at odd levels have outdegree 2.
A248100
Number of ordered trees with n edges such that non-leaf vertices at even levels have outdegree 1 and those at odd levels have outdegree 2.
Terms
- a(0) =1a(1) =1a(2) =0a(3) =1a(4) =2a(5) =1a(6) =2a(7) =6a(8) =6a(9) =7a(10) =20a(11) =30a(12) =34a(13) =75a(14) =140a(15) =182a(16) =322a(17) =644a(18) =972a(19) =1554a(20) =3024a(21) =5091a(22) =8052a(23) =14784a(24) =26378a(25) =43032a(26) =75504a(27) =136994a(28) =232232a(29) =399399
External references
- oeis: A248100