%I #17 Dec 18 2012 09:39:26

%S 1,1,1,1,2,1,1,4,2,1,7,4,2,13,7,4,1,25,13,7,2,1,48,25,13,3,2,1,92,48,

%T 25,6,3,2,176,92,48,12,6,3,1,338,176,92,23,12,6,1

%N Irregular triangle read by rows: T(n,k) = number of Huffman-equivalence classes of ternary trees with 2n+1 leaves and 3k leaves on the bottom level (n>=1, k>=1).

%D J. Paschke et al., Computing and estimating the number of n-ary Huffman sequences of a specified length, Discrete Math., 311 (2011), 1-7.

%e Triangle begins:

%e 1

%e 1

%e 1 1

%e 2 1 1

%e 4 2 1

%e 7 4 2

%e 13 7 4 1

%e 25 13 7 2 1

%e 48 25 13 3 2 1

%e 92 48 25 6 3 2

%e 176 92 48 12 6 3 1

%e 338 176 92 23 12 6 1

%Y Cf. A176431. A176463. Leading column is A176485.

%K nonn,more,tabf

%O 1,5

%A _N. J. A. Sloane_, Dec 07 2010