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A387375
Number of cycles in the n-Cameron graph.
2
3, 47, 397, 3031, 22713, 169643, 1266365, 9452431, 70554081, 526623027, 3930768005, 29339652055, 218994144553, 1634594548347, 12200779808717, 91067860276511, 679739762977393, 5073646662713283, 37870214249796885, 282667127347522151, 2109856161780989881
OFFSET
0,1
COMMENTS
The n-Cameron graph is defined for n >= 1. The sequence has been extended to a(0) using the recurrence. - Andrew Howroyd, Aug 31 2025
LINKS
Eric Weisstein's World of Mathematics, Cameron Graph.
Eric Weisstein's World of Mathematics, Graph Cycle.
FORMULA
a(n) = 10*a(n-1)-21*a(n-2)+16*a(n-3)-4*a(n-4).
G.f.: (3 + 17*x - 10*x^2)/((1 - x)^2*(1 - 8*x + 4*x^2)).
MATHEMATICA
Table[(Sqrt[3] ((Sqrt[3] - 1)^(2 n + 5) + (Sqrt[3] + 1)^(2 n + 5))/4 - 30 n - 39)/9, {n, 20}] // Expand
LinearRecurrence[{10, -21, 16, -4}, {47, 397, 3031, 22713}, 20]
CoefficientList[Series[(47 - 73 x + 48 x^2 - 12 x^3)/((-1 + x)^2 (1 - 8 x + 4 x^2)), {x, 0, 20}], x]
CROSSREFS
Cf. A387438.
Sequence in context: A277388 A245014 A247024 * A137611 A199106 A197203
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Aug 28 2025
EXTENSIONS
a(0) preprended by Andrew Howroyd, Aug 31 2025
STATUS
approved