A296916 List of coefficients of reduced chromatic polynomial of icosahedron, highest order terms first.

1, -24, 260, -1670, 6999, -19698, 36408, -40240, 20170

Offset

1,2

Comments

These are the coefficients when the chromatic polynomial of the icosahedron (see A296917) is divided by x*(x-1)*(x-2)*(x-3).

References

N. Biggs, Algebraic Graph Theory, 2nd ed. Cambridge University Press, 1993. See p. 69.

Links

Table of n, a(n) for n=1..9.

Example

The reduced chromatic polynomial is x^8-24*x^7+260*x^6-1670*x^5+6999*x^4-19698*x^3+36408*x^2-40240*x+20170.
Multiplying by x*(x-1)*(x-2)*(x-3) and expanding we get the chromatic polynomial for the icosahedron, which is x^12 - 30*x^11 + 415*x^10 - 3500*x^9 + 20023*x^8 - 81622*x^7 + 241605*x^6 - 517360*x^5 + 780286*x^4 - 782108*x^3 + 463310*x^2 - 121020*x.

Crossrefs

Cf. A296917, A218514.

Sequence in context: A296575 A009175 A308054 * A187380 A000145 A286346

Adjacent sequences: A296913 A296914 A296915 * A296917 A296918 A296919

Keyword

sign,fini,full

Author

N. J. A. Sloane, Dec 22 2017

Status

approved