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A371274 Irregular table read by rows: T(n,k) is the number of k-sided regions, k>=2, formed when n equally spaced points are placed around a circle and all pairs of points are joined by an interior arc whose radius equals the circle's radius.

%I A371274 #13 Mar 23 2024 21:21:04
%S A371274 1,3,3,4,0,1,10,10,5,1,12,6,14,56,21,0,7,1,8,48,32,0,0,0,1,27,144,54,
%T A371274 27,18,10,160,70,0,30,0,0,0,1,22,253,330,11,33,0,0,0,0,1,12,276,204,0,
%U A371274 24,26,624,403,130,104,0,0,0,0,0,0,1,14,630,448,112,70,14,14,0,0,0,0,0,1,45,960,915,165,165
%N A371274 Irregular table read by rows: T(n,k) is the number of k-sided regions, k>=2, formed when n equally spaced points are placed around a circle and all pairs of points are joined by an interior arc whose radius equals the circle's radius.
%C A371274 See A371253 and A371254 for images.
%F A371274 Sum of row n = A371253(n).
%e A371274 The table begins:
%e A371274 1;
%e A371274 3, 3;
%e A371274 4, 0, 1;
%e A371274 10, 10, 5, 1;
%e A371274 12, 6;
%e A371274 14, 56, 21, 0, 7, 1;
%e A371274 8, 48, 32, 0, 0, 0, 1;
%e A371274 27, 144, 54, 27, 18;
%e A371274 10, 160, 70, 0, 30, 0, 0, 0, 1;
%e A371274 22, 253, 330, 11, 33, 0, 0, 0, 0, 1;
%e A371274 12, 276, 204, 0, 24;
%e A371274 26, 624, 403, 130, 104, 0, 0, 0, 0, 0, 0, 1;
%e A371274 14, 630, 448, 112, 70, 14, 14, 0, 0, 0, 0, 0, 1;
%e A371274 45, 960, 915, 165, 165;
%e A371274 16, 1136, 704, 272, 192, 0, 16, 0, 0, 0, 0, 0, 0, 0, 1;
%e A371274 34, 1581, 1870, 238, 272, 17, 34, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%e A371274 18, 1656, 1386, 270, 288, 0, 18;
%e A371274 38, 2622, 2546, 646, 513, 38, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%e A371274 20, 2680, 2420, 820, 380, 20, 60, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%e A371274 63, 3297, 4725, 1050, 315, 42, 105;
%e A371274 22, 3696, 4136, 1342, 484, 22, 66, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
%Y A371274 Cf. A371253 (regions), A371254 (vertices), A371255 (edges), A331450, A359009, A359061, A359258.
%K A371274 nonn,tabf
%O A371274 2,2
%A A371274 _Scott R. Shannon_, Mar 17 2024