%I #12 Dec 20 2020 03:36:06
%S 1,1,1,1,1,1,1,1,1,1,1,1,2,3,5,6,8,9,11,11,12,11,11,9,8,6,5,3,2,1,1,1,
%T 1,1,2,4,8,14,26,44,76,125,206,327,521,802,1231,1845,2742,3987,5748,
%U 8124,11364,15615,21212,28336,37412,48597,62368,78810,98359
%N Triangle of coefficients of generating function of 4-ary rooted trees of height at most n.
%H E. M. Rains and N. J. A. Sloane, <a href="https://cs.uwaterloo.ca/journals/JIS/cayley.html">On Cayley's Enumeration of Alkanes (or 4-Valent Trees)</a>, J. Integer Sequences, Vol. 2 (1999), Article 99.1.1.
%H <a href="/index/Ro#rooted">Index entries for sequences related to rooted trees</a>
%e Triangle begins:
%e 1;
%e 1,1;
%e 1,1,1,1,1,1;
%e 1,1,1,2,3,5,6,8,9,11,11,12,11,11,9,8,6,5,3,2,1,1;
%K nonn,tabf,easy
%O 0,13
%A _N. J. A. Sloane_.