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%I
%S 0,0,0,0,0,0,1,18,36,81,9,0,0,0,0,0,0,0,0,0,0,0,0,1,126,36,180,135,18,
%T 45,9,0,0,0,0,0,0,0,0,0,0,1,288,126,54,90,36,18,9,0,0,1,450,306,72,18,
%U 576,369,207,126,0,9,0,0,0,0,0,0,0,0,0,1
%N Irregular table read by rows: n-sect the angles of a nonagon (enneagon). Then T(n,k) = number of k-sided polygons in that figure for k >= 3.
%C For n<=200 no polygon has more than 18 edges.
%C See A335781 for illustrations.
%H Lars Blomberg, <a href="/A335784/b335784.txt">Table of n, a(n) for n = 1..2217</a> (the first 200 rows)
%e The table begins:
%e 0, 0, 0, 0, 0, 0, 1;
%e 18;
%e 36, 81, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%e 126, 36;
%e 180, 135, 18, 45, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%e 288, 126, 54;
%e 90, 36, 18, 9, 0, 0, 1;
%e 450, 306, 72, 18;
%e 576, 369, 207, 126, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%Y Cf. A332427 (n-sected sides, not angles), A335781 (regions), A335782 (vertices), A335783 (edges).
%K tabf,nonn
%O 1,8
%A _Lars Blomberg_, Jun 24 2020
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