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A340685
The number of regions inside a concave circular triangle formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.
5
1, 12, 28, 102, 187, 462, 868, 1590, 3046, 4398, 6541, 8646, 12256, 15336, 20947, 26610, 33478, 41832, 50821, 64710, 77110, 97878, 113932, 136560, 160849, 185220, 216286, 246450, 289945, 324594, 372976, 426936, 472231, 537366, 598606, 685650, 762736, 858546, 943684, 1043442, 1143751, 1258800
OFFSET
1,2
COMMENTS
The terms are from numeric computation - no formula for a(n) is currently known.
LINKS
Scott R. Shannon, Regions for n = 2.
Scott R. Shannon, Regions for n = 3.
Scott R. Shannon, Regions for n = 4.
Scott R. Shannon, Regions for n = 6.
Scott R. Shannon, Regions for n = 8.
Scott R. Shannon, Regions for n = 10.
Scott R. Shannon, Regions for n = 14.
Scott R. Shannon, Regions for n = 15.
Wikipedia, Circular triangle.
CROSSREFS
Cf. A340686 (vertices), A340687 (edges), A340688 (n-gons), A340639, A007678, A092867.
Sequence in context: A204386 A078441 A351104 * A203026 A189539 A000546
KEYWORD
nonn
AUTHOR
STATUS
approved