A332608 Number of pentagons in the graph formed by drawing the lines connecting any two of the 2*(n+2) perimeter points of a 3 X (n+1) rectangular grid of points (or equally, a 2 X n grid of squares).

0, 0, 4, 12, 24, 28, 80, 128, 112, 200, 236, 356, 472, 652, 656, 940, 1040, 1300, 1600, 1948, 2048, 2588, 2856, 3260, 3716, 4492, 4572, 5324, 5904, 6508, 7200, 8144, 8664, 10296, 10548, 11664, 12580, 13860, 14596, 15980, 17312, 18516, 19692, 22152, 22912

Offset: 1

Author

Scott R. Shannon and N. J. A. Sloane, Mar 12 2020

Keywords

• nonn

Comments

See A331452 (the illustrations for T(n,2)) for pictures of these graphs.

Links

• Lars Blomberg, Table of n, a(n) for n = 1..100
• Scott R. Shannon, Data specifically for nX2 (or 2Xn) rectangles

Crossrefs

Cf. A331452, A331453, A331454, A331763, A331765, A331766, A332599, A332600, A331457, A332606, A332607, A332609.

Extensions

a(21) and beyond from Lars Blomberg, Apr 28 2020