OFFSET
19,1
COMMENTS
For n=3 to n=18 there are no n-gons that have 7-gon to k-gon contacts, where k>=7, so the table starts at n=19.
See A333654 for the number of 3-gon to k-gon contacts, with k>=3.
See A335614 for the number of 4-gon to k-gon contacts, with k>=4.
See A335646 for the number of 5-gon to k-gon contacts, with k>=5.
See A337330 for the number of 6-gon to k-gon contacts, with k>=6.
See A007678 for the number of regions and images of other n-gons.
LINKS
Scott R. Shannon, Image for n = 19. This is the first n-gon with 7-gon to 7-gon contacts.
Scott R. Shannon, Image for n = 59. This is the first n-gon with 7-gon to 8-gon contacts.
EXAMPLE
a(19) = 19, a(20-51) = 0, a(52) = 52, a(53-58) = 0.
The table from a(59) begins:
0, 118,
9;
61;
0;
63;
0;
0;
0;
0;
0;
138;
70;
0;
72;
73;
148;
0;
0;
0;
0;
158;
80;
0;
82;
83;
0;
0;
172;
0;
0;
178;
540;
0;
0;
93, 0, 93;
282;
95;
96;
194;
294;
0, 198, 99;
0;
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Scott R. Shannon, Jan 14 2021
STATUS
approved