login
Square array read by antidiagonals giving number of binary trees of height n with k points on the n-th level (n,k>0).
3

%I #17 Aug 30 2023 07:29:23

%S 1,0,2,0,1,8,0,0,8,80,0,0,4,144,4160,0,0,1,168,13888,5632640,0,0,0,

%T 138,31776,36109952,5163215782400,0,0,0,80,54792,158572864,

%U 64827181969920,2169236189050838782284800,0,0,0,32,74624,531441232,552146121580800

%N Square array read by antidiagonals giving number of binary trees of height n with k points on the n-th level (n,k>0).

%H H. Bottomley, <a href="/A001699/a001699.gif">Illustration of initial terms</a>

%F T(n,k) = Sum_{2j >= k} (C(2j,k)*T(n-1,j)) starting with T(1,1) = 1 and T(1,k) = 0 if k>1.

%e Square array starts:

%e 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...

%e 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, ...

%e 8, 8, 4, 1, 0, 0, 0, 0, 0, 0, ...

%e 80, 144, 168, 138, 80, 32, 8, 1, 0, 0, ...

%e ...

%Y Row sums are A001699.

%Y Cf. A073345, A073429.

%K nonn,tabl

%O 1,3

%A _Henry Bottomley_, Oct 29 2001

%E More terms from _Sean A. Irvine_, Aug 30 2023