MathDB
Putnam 2017 A6

Source:

December 3, 2017
PutnamPutnam 2017

Problem Statement

The 3030 edges of a regular icosahedron are distinguished by labeling them 1,2,,30.1,2,\dots,30. How many different ways are there to paint each edge red, white, or blue such that each of the 20 triangular faces of the icosahedron has two edges of the same color and a third edge of a different color?