A335192 a(n) is the number of regions inside an n-gon formed by the straight line segments connecting vertex k to vertex 3k mod n.

1, 2, 4, 7, 8, 6, 12, 19, 23, 18, 31, 39, 37, 28, 56, 57, 68, 60, 76, 93, 103, 72, 119, 133, 129, 126, 164, 163, 184, 146, 196, 223, 239, 206, 263, 283, 277, 240, 328, 317, 356, 336, 372, 409, 431, 348, 463, 489, 481, 474, 548, 543, 584, 510, 604, 651, 679

Offset

3,2

Comments

The envelope of the lines form a nephroid.

Links

Lars Blomberg, Table of n, a(n) for n = 3..300

Lars Blomberg, Illustration for n = 10

Lars Blomberg, Illustration for n = 20

Lars Blomberg, Illustration for n = 40

Lars Blomberg, Illustration for n = 200

Crossrefs

Cf. A335193 (edges), A335194 (vertices), A335195 (n-gons).

Sequence in context: A094541 A166928 A237199 * A092577 A182842 A009282

Adjacent sequences: A335189 A335190 A335191 * A335193 A335194 A335195

Keyword

nonn

Author

Lars Blomberg, May 26 2020

Status

approved