English

Cutting a Pancake with an Exotic Knife

Combinatorics 2026-04-21 v3

Abstract

In the first chapter of their classic book "Concrete Mathematics", Graham, Knuth, and Patashnik consider the maximum number of pieces that can be obtained from a pancake by making n cuts with a knife blade that is straight, or bent into a V, or bent twice into a Z. We extend their work by considering knives, or "cookie-cutters", of even more exotic shapes, including a k-armed V, a chain of k connected line segments, long-legged versions of the letters A, E, H, L, M, T, W, or X, a convex polygon, a circle, a phi, a figure 8, a pentagram, a hexagram, or a lollipop (or qoppa). We also consider "constrained" versions of the long-legged letters A, H, L, T, and X. In most cases we are able to determine the maximum number of pieces, although for the constrained A and the lollipop we can only give bounds.

Cite

@article{arxiv.2511.15864,
  title  = {Cutting a Pancake with an Exotic Knife},
  author = {David O. H. Cutler and Jonas Karlsson and Neil J. A. Sloane},
  journal= {arXiv preprint arXiv:2511.15864},
  year   = {2026}
}

Comments

47 pages, 8 tables, 47 figures. Added a third author, new sections, some proofs tightened

R2 v1 2026-07-01T07:46:10.963Z