This pattern breaks, but for a good reason | Moser's circle problem (updated) - Summary

Summary

This text discusses Moser's Circle Problem, a math puzzle involving points and chords on a circle. The problem explores how many regions the circle is divided into as more points are added. The author explains the process, introduces Euler's formula, and connects it to Pascal's triangle to understand the pattern of powers of two. The problem serves as a cautionary tale about relying on patterns without proof, emphasizing the importance of deeper understanding in mathematics.

Facts

Here are the key facts extracted from the text:

1. Moser's Circle Problem involves connecting points on a circle with chords, dividing the circle into regions.
2. Adding a third point and connecting it creates four regions, and this pattern continues.
3. The number of regions after adding N points is 1 + N choose 2 + N choose 4.
4. Euler's Characteristic Formula (V - E + 1) helps count the regions created by intersecting chords.
5. Euler's Formula applies because the intersections create new vertices and edges.
6. Pascal's Triangle demonstrates a pattern of powers of two when summing rows.
7. The formula for counting regions relates to adding up elements in Pascal's Triangle, explaining the powers of two pattern.
8. The pattern breaks at N = 6, falling one short of the expected power of two.