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

Author

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

Keywords

• nonn

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).

Extensions

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