A367279 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 edges in the resulting planar graph.

4, 16, 156, 788, 2880, 6468, 15800, 27828, 49936, 78732, 134656, 173396, 286676, 373004, 495300, 659556, 938328, 1086108, 1525216, 1727060, 2187912, 2724272, 3468932, 3730780, 4781740, 5611000, 6549252, 7404820, 9272476, 9645308, 12278824, 13302464, 15300332, 17565324, 19475404, 20973584

Offset

0,1

Comments

See A367276 for further information. See A367276 and A367278 for images of the square.

Links

Table of n, a(n) for n=0..35.

Formula

a(n) = A367276(n) + A367278(n) - 1 (Euler).

Crossrefs

Cf. A367276 (vertices), A367277 (interior vertices), A367278 (regions).

Sequence in context: A005739 A279887 A226588 * A318641 A005741 A033911

Adjacent sequences: A367276 A367277 A367278 * A367280 A367281 A367282

Keyword

nonn

Author

Scott R. Shannon, Nov 11 2023

Status

approved