A367277 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 interior vertices in the resulting planar graph.

0, 1, 57, 329, 1317, 2861, 7417, 12801, 23329, 36549, 64625, 80085, 138261, 176829, 233705, 311949, 455205, 513205, 741889, 819509, 1046161, 1310673, 1692869, 1772001, 2315189, 2713893, 3165017, 3552641, 4538729, 4602865, 6015437, 6432553, 7421213, 8550349, 9439481, 10063849, 12635621

Offset

0,3

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 = 10.

Formula

a(n) = A367279(n) - A367278(n) - 4*n - 3 (Euler).

Crossrefs

Cf. A367276 (interior), A367278 (regions), A367279 (edges).

Sequence in context: A048422 A157651 A251263 * A371515 A043399 A038482

Adjacent sequences: A367274 A367275 A367276 * A367278 A367279 A367280

Keyword

nonn

Author

Scott R. Shannon, Nov 11 2023

Status

approved