A369177 Number of edges in a graph of n adjacent rectangles in a row with all possible diagonals drawn, as in A306302, but without the rectangles' edges which are perpendicular to the row.

6, 24, 66, 152, 318, 576, 998, 1608, 2474, 3600, 5162, 7100, 9670, 12772, 16546, 21036, 26622, 33024, 40814, 49716, 60006, 71560, 85158, 100264, 117626, 136780, 158358, 182080, 209106, 238312, 271314, 307304, 346866, 389488, 436286, 486444, 542026, 601436, 665814, 734504, 809882, 889544

Offset: 1

Author

Scott R. Shannon, Jan 15 2024

Keywords

• nonn

Comments

See A369175 and A369176 for images of the graph.

Crossrefs

Cf. A369175 (regions), A369176 (vertices), A369178 (k-gons), A306302, A331757, A290132, A368757.

Formula

a(n) = A369175(n) + A369176(n) - 1 by Euler's formula.