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A359691
Number of crossings in a regular drawing of a complete bipartite graph where the vertex positions on each part equal the Farey series of order n.
4
1, 7, 59, 275, 1949, 3971, 20333, 45705, 120899, 205233, 629761, 897707, 2334291, 3461329, 5516985, 8467899
OFFSET
1,2
COMMENTS
The number of vertices along each edge is A005728(n). No formula for a(n) is known.
See A359690 for images of the graph.
LINKS
Eric Weisstein's World of Mathematics, Complete Bipartite Graph.
Wikipedia, Farey sequence.
FORMULA
a(n) = A359690(n) - 2*A005728(n).
CROSSREFS
Cf. A359690 (vertices), A359692 (regions), A359693 (edges), A359694 (k-gons), A005728, A159065, A331755, A359654, A358887, A358883, A006842, A006843.
Sequence in context: A142511 A236070 A059705 * A218201 A015568 A322667
KEYWORD
nonn,more
AUTHOR
STATUS
approved