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A335350
a(n) is the number of regions formed in a square by dividing each of its sides into n equal parts giving a total of 4*n nodes and drawing straight line segments from node k to node (k+n+1) mod 4*n, 0 <= k < 4*n.
5
4, 25, 37, 81, 109, 169, 205, 289, 341, 441, 485, 625, 701, 825, 913, 1089, 1189, 1369, 1461, 1661, 1805, 2025, 2141, 2389, 2549, 2809, 2929, 3249, 3405, 3721, 3901, 4205, 4421, 4753, 4913, 5329, 5549, 5913, 6105, 6561, 6781, 7225, 7453, 7885, 8189, 8649
OFFSET
1,1
COMMENTS
For n>1, a(n)-1 is divisible by 4.
LINKS
Lars Blomberg, Illustration for n=3
Lars Blomberg, Illustration for n=4
Lars Blomberg, Illustration for n=5
Lars Blomberg, Illustration for n=10
Lars Blomberg, Illustration for n=16
Lars Blomberg, Illustration for n=35
CROSSREFS
Cf. A335351 (edges), A335352 (vertices), A335353 (n-gons), A335354 (edges in central polygon), A255011, A335057, A335192.
Sequence in context: A267765 A376157 A231176 * A199772 A245697 A089767
KEYWORD
nonn
AUTHOR
Lars Blomberg, Jun 03 2020
STATUS
approved