30 May
2020
30 May
'20
2:29 p.m.
Allan Wechsler <acwacw@gmail.com> wrote:
"Keith F. Lynch" <kfl@KeithLynch.net> wrote:
Find a connected graph of girth 5 (i.e. no loops of size 3 or 4) in which every integer is a vertex, every vertex has the same valence, and every vertex is part of a loop of size 5.
Yes, I have a solution, unless I'm confused.
All even numbers 2n are connected to 2n+1, 2n+2, and 2n-2. All odd numbers 2n+1 are connected to 2n, 2n+5, and 2n-4. I am pretty sure this graph is cubic of girth 5.
3 is connected to 7, but 7 is not connected to 3.