%I #11 Apr 19 2016 07:48:18

%S 1,47,1112,11743,82988,433372,1820163,6459496,20287372,57129426,

%T 147915285,356109110,804785159,1722171831

%N Number of non-equivalent (mod D_3) ways to arrange 6 indistinguishable points on a triangular grid of side n so that no three points are collinear.

%C Column 6 of triangle A234350.

%C Without the restriction "non-equivalent (mod D_3)" the numbers are given by A194134.

%e There is a(4) = 1 non-equivalent way to arrange 6 indistinguishable points (x) on a triangular grid of side 4:

%e .

%e x x

%e x . x

%e . x x .

%Y Cf. A234350, A194134

%Y Arranging 3 points: A234351

%Y Arranging 4 points: A234352

%Y Arranging 5 points: A234353

%K nonn,more

%O 4,2

%A _Heinrich Ludwig_, Dec 30 2013

%E a(14)-a(17) from _Heinrich Ludwig_, Apr 19 2016