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A370976
Let G_n denote the planar graph defined in A358746 with the addition, if n is odd, of the circle containing the initial n points; sequence gives the number of regions in G_n.
7
1, 1, 10, 12, 71, 85, 288, 264, 811, 821, 1904, 1740, 3823, 3725, 6886, 6448, 11765, 11125, 18336, 17160, 27637, 26797, 40090, 37176, 56851, 54653, 77734, 74788, 103763, 101041, 136866, 131744, 176617, 172109, 223966, 216900, 281127, 273829, 348622, 337480, 425991, 416641
OFFSET
1,3
COMMENTS
If n is even the circle through the initial n points is already part of the graph.
In other words, draw a circle and place n equally spaced points around it; for each pair of poins X, Y, draw a circle with diameter XY; the union of these circles is the graph G_n.
For the numbers of vertices and edges in G_n see A358746 and A370977.
For other images for n even, see A358782 (for even n, A358782 and the present sequence agree).
LINKS
Scott R. Shannon, Image for n = 3.
Scott R. Shannon, Image for n = 4.
Scott R. Shannon, Image for n = 6.
Scott R. Shannon, Image for n = 7.
Scott R. Shannon, Image for n = 8.
Scott R. Shannon, Image for n = 11.
FORMULA
a(n) = A358782(n) if n even, a(n) = A358782(n) + n if n odd.
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved