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A288917
Number of 6-cycles in the n X n queen graph.
3
0, 0, 976, 26414, 207136, 951750, 3190304, 8721576, 20615340, 43736788, 85332868, 155691014, 268995384, 444000894, 705336724, 1083967932, 1619250600, 2358809948, 3361809572, 4697700286, 6451359236, 8719953330, 11620829368
OFFSET
1,3
LINKS
Eric Weisstein's World of Mathematics, Graph Cycle
Eric Weisstein's World of Mathematics, Queen Graph
Index entries for linear recurrences with constant coefficients, signature (0, 3, 2, -1, -5, -6, -1, 6, 11, 6, -4, -10, -10, -4, 6, 11, 6, -1, -6, -5, -1, 2, 3, 0, -1).
FORMULA
a(n)=3*a(n-2)+2*a(n-3)-a(n-4)-5*a(n-5)-6*a(n-6)-a(n-7)+6*a(n-8)+11*a(n-9)+6*a(n-10)-4*a(n-11)-10*a(n-12)-10*a(n-13)-4*a(n-14)+6*a(n-15)+11*a(n-16)+6*a(n-17)-a(n-18)-6*a(n-19)-5*a(n-20)-a(n-21)+2*a(n-22)+3*a(n-23)-a(n-25).
MATHEMATICA
LinearRecurrence[{0, 3, 2, -1, -5, -6, -1, 6, 11, 6, -4, -10, -10, -4, 6, 11, 6, -1, -6, -5, -1, 2, 3, 0, -1}, {0, 0, 976, 26414, 207136, 951750, 3190304, 8721576, 20615340, 43736788, 85332868, 155691014, 268995384, 444000894, 705336724, 1083967932, 1619250600, 2358809948, 3361809572, 4697700286, 6451359236, 8719953330, 11620829368, 15285494276, 19871396864}, 30]
CROSSREFS
Cf. A144298 (3-cycles), A156001 (4-cycles), A288916 (5-cycles).
Sequence in context: A233984 A205252 A190400 * A264130 A282405 A077362
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Jun 19 2017
STATUS
approved