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%I #11 Apr 19 2016 07:48:38
%S 8,140,1290,7374,32477,116420,358112,976063,2425756,5560046,11946923,
%T 24274195,46975815,87140153
%N Number of non-equivalent (mod D_3) ways to arrange 5 indistinguishable points on a triangular grid of side n so that no three points are collinear.
%C Column 5 of triangle A234350.
%C Without the restriction "non-equivalent (mod D_3)" the numbers are given by A194133.
%e There are a(4) = 8 non-equivalent ways to arrange 5 indistinguishable points (x) on a triangular grid of side 4. Some examples:
%e x x . . .
%e x x . . x . x x x .
%e . . . x . x x . x . x . x . x
%e . x x . . x x . . x x . x . . x . x . x
%Y Cf. A234350, A194133
%Y Arranging 3 points: A234351
%Y Arranging 4 points: A234352
%Y Arranging 6 points: A234354
%K nonn,more
%O 4,1
%A _Heinrich Ludwig_, Dec 30 2013
%E a(14)-a(17) from _Heinrich Ludwig_, Apr 19 2016