A371208 Number of minimum vertex colorings in the complement of the wheel graph on n nodes.

1, 8, 90, 36, 672, 192, 5400, 1200, 47520, 8640, 458640, 70560, 4838400, 645120, 55520640, 6531840, 689472000, 72576000, 9220780800, 878169600, 132204441600, 11496038400, 2023781760000, 161902540800, 32953394073600, 2440992153600, 568838350080000, 39230231040000

Offset

4,2

Links

Table of n, a(n) for n=4..31.

Eric Weisstein's World of Mathematics, Minimum Vertex Coloring.

Eric Weisstein's World of Mathematics, Wheel Complement Graph.

Formula

a(n) = (n-1)*((n-1)/2)! for n odd.

a(4) = 1; a(n) = (1/4)*(n - 1)*n^2*(n/2 - 1)! for n even. - Detlef Meya, Apr 14 2024

Mathematica

a[4]:=1; a[n_]:=If[Mod[n, 2]==0, (1/4)*(n-1)*n^2*(n/2-1)!, (n-1)*((n-1)/2)!]; Flatten[Table[a[n], {n, 4, 31}]] (* Detlef Meya, Apr 14 2024 *)

Crossrefs

Sequence in context: A131655 A105718 A045732 * A077192 A128304 A247728

Adjacent sequences: A371205 A371206 A371207 * A371209 A371210 A371211

Keyword

nonn,changed

Author

Eric W. Weisstein, Mar 15 2024

Extensions

More terms (20-31) from Detlef Meya, Apr 14 2024

Status

approved