[Kwant] Number of equidistant neighbors on honeycomb lattice

What is the number of neighbors on graphene lattice?

That question bothered me for 2-3 years. Finally, I found a way to solve the problem.

Did I find a something was already known? I guess not.

The issue may probably interest many of you on this list.

Please let me know what you think about my "solution"? I am myself very curious.

I am, BTW, interested in contacts (talking, solving problems, doing the work together, publishing together) with people who are on subjects close to graphene. Do not hesitate to contact me.

*Number of equidistant neighbors on honeycomb lattice*:

https://arxiv.org/abs/2004.11840

zb.