A334280 Irregular table read by rows: T(n, k) is the coefficient of x^k in the chromatic polynomial of the 1-skeleton of the n-dimensional demihypercube, 0 <= k <= 2^(n-1).

0, 1, 0, -1, 1, 0, -6, 11, -6, 1, 0, -2790, 7467, -7852, 4300, -1346, 244, -24, 1, 0, -36586695600, 132041735820, -208601259660, 194243767689, -120509323400, 53195294240, -17371817260, 4296667608, -815202340, 119111090, -13339000, 1127752, -69860, 3000, -80, 1

Offset

1,7

Links

Table of n, a(n) for n=1..36.

Eric Weisstein's World of Mathematics, Chromatic Polynomial

Eric Weisstein's World of Mathematics, Halved Cube Graph

Wikipedia, Demihypercube

Example

n\k| 0     1    2     3    4     5   6   7 8
---+----------------------------------------
  1| 0     1
  2| 0    -1    1
  3| 0    -6   11    -6    1
  4| 0 -2790 7467 -7852 4300 -1346 244 -24 1

Mathematica

T[n_, k_] := Coefficient[ChromaticPolynomial[GraphData[{"HalvedCube", n}], x], x, k]

Crossrefs

Cf. A048994 (simplex), A334278 (hypercube), A334279 (cross-polytope).

Sequence in context: A258054 A106540 A212208 * A134012 A103704 A135998

Adjacent sequences: A334277 A334278 A334279 * A334281 A334282 A334283

Keyword

sign,tabf

Author

Peter Kagey, Apr 22 2020

Status

approved