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Irregular table read by rows: row n gives the number of 4-gon to k-gon contacts, with k>=4, for a regular n-gon with all diagonals drawn.
6

%I #33 Aug 29 2020 02:52:19

%S 0,0,0,6,0,5,24,18,36,18,90,20,110,110,44,168,208,208,52,378,140,570,

%T 330,330,640,320,32,918,646,238,34,34,990,1254,1330,304,38,76,1540,

%U 1040,80,2478,1722,1008,42,2948,1408,44,132,132,2852,2254,1012,92,46,3624,1536,144

%N Irregular table read by rows: row n gives the number of 4-gon to k-gon contacts, with k>=4, for a regular n-gon with all diagonals drawn.

%C See A333654 for the number of 3-gon to k-gon contacts, with k>=3.

%C See A335646 for the number of 5-gon to k-gon contacts, with k>=5.

%C See A337330 for the number of 6-gon to k-gon contacts, with k>=6.

%C See A007678 for the number of regions and images of other n-gons.

%H Scott R. Shannon, <a href="/A335614/a335614.png">Image for n=6 with edge-number coloring</a>. This is the first n-gon with 4-gon to 4-gon contacts.

%H Scott R. Shannon, <a href="/A335614/a335614_1.png">Image for n=7 with edge-number coloring</a>. This is the first n-gon with 4-gon to 5-gon contacts.

%H Scott R. Shannon, <a href="/A335614/a335614_2.png">Image for n=9 with edge-number coloring</a>. This is the first n-gon with 4-gon to 6-gon contacts.

%H Scott R. Shannon, <a href="/A335614/a335614_3.png">Image for n=17 with edge-number coloring</a>. This is the first n-gon with 4-gon to 7-gon and 4-gon to 8-gon contacts.

%H Scott R. Shannon, <a href="/A335614/a335614_5.png">Image for n=31 with edge-number coloring</a>. This is the first n-gon with 4-gon to 10-gon contacts.

%H Scott R. Shannon, <a href="/A335614/a335614_8.png">Image for n=31 with random distance-based coloring</a>.

%H Scott R. Shannon, <a href="/A335614/a335614_6.png">Image for n=29 with edge-number coloring</a>. This is the first n-gon with 4-gon to 11-gon contacts.

%H Scott R. Shannon, <a href="/A335614/a335614_4.png">Image for n=18 with edge-number coloring</a>. This is the only n-gon from n=13 to n=33 that has only 4-gon to 3-gon and 4-gon to 4-gon contacts. It is likely the last n-gon with this property.

%H Scott R. Shannon, <a href="/A335614/a335614_7.png">Image for n=18 with random distance-based coloring</a>.

%e The table begins:

%e .

%e 0;

%e 0;

%e 0;

%e 6;

%e 0,5;

%e 24;

%e 18,36,18;

%e 90,20;

%e 110,110,44;

%e 168;

%e 208,208,52;

%e 378,140;

%e 570,330,330;

%e 640,320,32;

%e 918,646,238,34,34;

%e 990;

%e 1254,1330,304,38,76;

%e 1540,1040,80;

%e 2478,1722,1008,42;

%e 2948,1408,44,132,132;

%e 2852,2254,1012,92,46;

%e 3624,1536,144;

%e 4650,3600,1450,150,150;

%e 4784,3380,572,52;

%e 6696,4968,2160,54,54;

%e 7280,3752,2072,168;

%e 8990,7308,3016,0,232,0,0,58;

%e 7770,1200,300;

%e 13020,9920,3472,186,434,0,124;

%e 12160,8576,2048,256;

%e 14784,11418,5742,792,330;

%Y Cf. A333654 (3-gon contacts), A335646 (5-gon contacts), , A337330 (6-gon contacts), A007678, A135565, A007569, A062361, A331450, A331451.

%K nonn,tabf

%O 3,4

%A _Scott R. Shannon_, Aug 23 2020