|
%I #5 Mar 30 2012 17:23:03
%S 1,1,2,1,1,1,1,2,3,1,1,2,2,2,1,3,4,1,2,2,1,1,3,2,3,1,4,5,1,1,1,1,2,1,
%T 1,2,2,2,2,2,1,2,3,3,3,1,1,4,2,4,1,5,6
%N Irregular triangle of possible factorizations of the trinomial x^n + A*x^m + B, where A and B are rational with A*B nonzero and n > m.
%C As shown in the example below, for each n, every row sums to n. The rows are a subset of rows in A080576, which lists all partitions of n in graded reflected lexicographic order. Currently, the rows for n=7 are not proved. They are assumed to be {1, 3, 3}, {1, 2, 4}, {3, 4}, {1, 1, 5}, {2, 5}, {1, 6}, {7}.
%H Andrew Bremner and Maciej Ulas, <a href="http://arxiv.org/abs/1112.4267">On the reducibility type of trinomials</a>, arxiv 1112.4267
%e The first rows:
%e 1, 1
%e 2
%e 1, 1, 1
%e 1, 2
%e 3
%e 1, 1, 2
%e 2, 2
%e 1, 3
%e 4
%e 1, 2, 2
%e 1, 1, 3
%e 2, 3
%e 1, 4
%e 5
%Y Cf. A178868 (note that the number A multiplies a linear term only).
%K nonn,tabf,more
%O 2,3
%A _T. D. Noe_, Dec 20 2011
|
