A367278 Place n equally spaced points on each side of a square, and join each of these points by a chord to the 3*n new points on the other three sides: sequence gives number of regions in the resulting planar graph.

1, 8, 88, 444, 1544, 3584, 8356, 14996, 26572, 42144, 69988, 93264, 148364, 196120, 261536, 347544, 483056, 572832, 783252, 907472, 1141668, 1413512, 1775972, 1958684, 2466452, 2897004, 3384128, 3852068, 4733632, 5042324, 6263264, 6869784, 7878988, 9014840, 10035784, 10909592, 13109608

Offset

0,2

Comments

See A367276 for further information.

Links

Table of n, a(n) for n=0..36.

Scott R. Shannon, Image for n = 1.

Scott R. Shannon, Image for n = 2.

Scott R. Shannon, Image for n = 3.

Scott R. Shannon, Image for n = 4.

Scott R. Shannon, Image for n = 5.

Scott R. Shannon, Image for n = 9.

Scott R. Shannon, Image for n = 10.

Formula

a(n) = A367279(n) - A367276(n) + 1 (Euler).

Crossrefs

Cf. A367276 (vertices), A367277 (interior vertices), A367279 (edges).

Sequence in context: A299671 A299749 A300263 * A030984 A109021 A271939

Adjacent sequences: A367275 A367276 A367277 * A367279 A367280 A367281

Keyword

nonn

Author

Scott R. Shannon, Nov 11 2023

Status

approved