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A369176
Number of vertices 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.
4
5, 13, 31, 67, 139, 247, 429, 691, 1067, 1543, 2217, 3047, 4169, 5495, 7117, 9031, 11449, 14179, 17547, 21379, 25835, 30755, 36613, 43091, 50605, 58775, 68035, 78171, 89831, 102335, 116593, 132079, 149181, 167391, 187497, 208983, 232977, 258351, 285957, 315323, 347777, 381867, 419371
OFFSET
1,1
LINKS
Scott R. Shannon, Image for n = 1.
Scott R. Shannon, Image for n = 2.
Scott R. Shannon, Image for n = 8.
FORMULA
a(n) = A369177(n) - A369175(n) + 1 by Euler's formula.
CROSSREFS
Cf. A369175 (regions), A369177 (edges), A369178 (k-gons), A306302, A331755, A368756.
Sequence in context: A109419 A335307 A067333 * A209009 A118646 A097969
KEYWORD
nonn
AUTHOR
Scott R. Shannon, Jan 15 2024
STATUS
approved