%I #12 Mar 08 2017 11:55:57
%S 1,1,2,2,1,3,6,6,1,4,16,32,24,7,1,5,32,113,200,176,66,6,7,60,329,1053,
%T 1976,2096,1162,302,34,2,8,100,790,3932,12565,25676,32963,25638,11294,
%U 2493,222,7,10,160,1702,11988,57275,187984,425329,658608,684671,462519
%N Triangle T(n, k) = Numbers of non-equivalent (mod D_3) ways to place k points on a triangular grid of side n so that no two of them are adjacent. Triangle read by rows.
%C Triangle T(n, k) is irregularly shaped: 1 <= k <= A239438(n). First row corresponds to n = 1.
%C The maximal number of points that can be placed on a triangular grid of side n so that no two of them are adjacent is given by A239438(n).
%C Without the restriction "non-equivalent (mod D_3)" numbers are given by A239567.
%H Heinrich Ludwig, <a href="/A239572/b239572.txt">Table of n, a(n) for n = 1..136</a>
%e Triangle begins
%e 1;
%e 1;
%e 2, 2, 1;
%e 3, 6, 6, 1;
%e 4, 16, 32, 24, 7, 1;
%e 5, 32, 113, 200, 176, 66, 6;
%e 7, 60, 329, 1053, 1976, 2096, 1162, 302, 34, 2;
%e 8, 100, 790, 3932, 12565, 25676, 32963, 25638, 11294, 2493, 222, 7;
%Y Cf. A239438, A239567.
%Y Column 1 is A001399,
%Y Column 2 is A032091,
%Y Column 3 is A239573,
%Y Column 4 is A239574,
%Y Column 5 is A239575,
%Y Column 6 is A279446.
%K nonn,tabf
%O 1,3
%A _Heinrich Ludwig_, Mar 22 2014