A335353 - OEIS

%I #8 Jun 07 2020 10:26:21

%S 4,16,8,0,0,0,1,32,5,32,40,8,0,0,1,64,28,16,0,0,0,0,0,0,1,80,56,24,8,

%T 0,0,0,0,0,0,0,0,0,1,96,84,24,0,0,0,0,0,0,1,128,100,40,20,0,0,0,0,0,0,

%U 0,0,0,1,144,156,32,0,8,0,0,0,0,0,0,0,0,0,0,0,0,1

%N Irregular table read by rows: Take a square and divide each of its sides into n equal parts giving a total of 4*n nodes, draw straight line segments from node k to node (k+n+1) mod 4*n, 0 <= k < 4*n. Then T(n,k) = number of k-sided polygons in that figure for k >= 3.

%C See A335350 for illustrations.

%H Lars Blomberg, <a href="/A335353/b335353.txt">Table of n, a(n) for n = 1..10000</a>

%e Table begins:

%e 4;

%e 16, 8, 0, 0, 0, 1;

%e 32, 5;

%e 32, 40, 8, 0, 0, 1;

%e 64, 28, 16, 0, 0, 0, 0, 0, 0, 1;

%e 80, 56, 24, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;

%e 96, 84, 24, 0, 0, 0, 0, 0, 0, 1;

%e 128, 100, 40, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;

%e 144, 156, 32, 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;

%e 168, 188, 64, 16, 0, 4, 0, 0, 0, 0, 0, 0, 0, 1;

%e 200, 228, 40, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;

%e 248, 252, 88, 24, 8, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;

%Y Cf. A335350 (regions), A335351 (edges), A335352 (vertices), A335354 (edges in central polygon), A255011, A335057, A335192.

%K nonn,tabf

%O 1,1

%A _Lars Blomberg_, Jun 04 2020