A330850 The number of vertices inside a cross with width 3 and height n (see Comments in A331455 for definition) formed by the straight line segments mutually connecting all vertices and all points.

45, 69, 119, 219, 357, 575, 871, 1301, 1815, 2543, 3435, 4635, 6023, 7731, 9727, 12259, 15087, 18585, 22543, 27165, 32215, 38239, 44899, 52631, 60979, 70465, 80815, 92749, 105511, 120079, 135867, 153331, 171851, 192311, 214159, 238583, 264323, 292371, 322171

Offset

2,1

Comments

See the links in A331455 for images of the crosses.

Links

Lars Blomberg, Table of n, a(n) for n = 2..50

Crossrefs

Cf. A331455 (regions), A330848 (n-gons), A330851 (edges), A333035 (cross with equal length arms).

Sequence in context: A038494 A026043 A372291 * A053720 A259218 A093764

Adjacent sequences: A330847 A330848 A330849 * A330851 A330852 A330853

Keyword

nonn

Author

Scott R. Shannon and N. J. A. Sloane, Mar 07 2020

Extensions

Corrected offset and a(11) and beyond from Lars Blomberg, May 31 2020

Status

approved