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%I #22 Dec 05 2022 04:41:03
%S 0,0,1,1,0,1,4,3,3,2,70,60,54,12,6,2980,3512,2088,704,156,28,268444,
%T 315840,176928,59204,13488,1920,193,36387789,42112416,22965696,
%U 7722144,1759104,277344,28992,1743,6789078267,7716280320,4153217280,1393136640,321814080,53061120,6216960,483840,20640
%N Triangle read by rows: T(n,k) is the number of polygons with 2*n sides, of which k run through the center of a circle, on the circumference of which the 2*n vertices of the polygon are arranged at equal spacing, up to rotation and reflection.
%C By "2*n-sided polygons" we mean the polygons that can be drawn by connecting 2*n equally spaced points on a circle.
%C T(0,0)=0 and T(0,1)=1 by convention.
%C The sequence is limited to even-sided polygons, since all odd-sided polygons have no side passing through the center.
%H Ludovic Schwob, <a href="/A358329/b358329.txt">Table of n, a(n) for n = 0..5150</a>
%e Triangle begins:
%e 0;
%e 0, 1;
%e 1, 0, 1;
%e 4, 3, 3, 2;
%e 70, 60, 54, 12, 6;
%Y Row sums give A094157(n).
%Y Cf. A330662.
%K nonn,tabl
%O 0,7
%A _Ludovic Schwob_, Nov 09 2022
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