cp's OEIS Frontend

A176452 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).

%I A176452 #17 Dec 18 2012 09:39:26
%S A176452 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 A176452 25,6,3,2,176,92,48,12,6,3,1,338,176,92,23,12,6,1
%N A176452 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 A176452 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 A176452 Triangle begins:
%e A176452 1
%e A176452 1
%e A176452 1 1
%e A176452 2 1 1
%e A176452 4 2 1
%e A176452 7 4 2
%e A176452 13 7 4 1
%e A176452 25 13 7 2 1
%e A176452 48 25 13 3 2 1
%e A176452 92 48 25 6 3 2
%e A176452 176 92 48 12 6 3 1
%e A176452 338 176 92 23 12 6 1
%Y A176452 Cf. A176431. A176463. Leading column is A176485.
%K A176452 nonn,more,tabf
%O A176452 1,5
%A A176452 _N. J. A. Sloane_, Dec 07 2010