A304525 Star chromatic indices of complete graphs.

0, 1, 3, 5, 9, 12, 14, 14, 18

Offset

1,3

Comments

The star chromatic index of a graph is the minimum number of colors needed to color the edges of a graph such that adjacent edges receive different colors and that on every path and cycle on four edges there are at least three different colors. The values a(n) are the star chromatic indices of the complete graph K_n. For the complete graph K_n, Dvořák, Mohar and Šámal conjectured that the star chromatic index is linear in n. For now, only the bounds up to n=9 are known. For n=10, the index is between 20 and 22.

Links

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

Z. Dvořák, B. Mohar and R. Šámal, Star chromatic index, arXiv:1011.3376 [math.CO],

Z. Dvořák, B. Mohar and R. Šámal, Star chromatic index, J. Graph Theory 72 (2013), 313-326.

Crossrefs

Sequence in context: A120806 A020946 A352596 * A310039 A091785 A191403

Adjacent sequences: A304522 A304523 A304524 * A304526 A304527 A304528

Keyword

nonn,hard

Author

Borut Lužar, May 14 2018

Status

approved