data/problems/393.yml
---
:id: 393
:name: Migrating ants
:url: https://projecteuler.net/problem=393
:content: "An <var>n</var>×<var>n</var> grid of squares contains <var>n</var><sup>2</sup>
ants, one ant per square. \nAll ants decide to move simultaneously to an adjacent
square (usually 4 possibilities, except for ants on the edge of the grid or at the
corners). \nWe define <var>f</var>(<var>n</var>) to be the number of ways this
can happen without any ants ending on the same square and without any two ants crossing
the same edge between two squares.\n\nYou are given that <var>f</var>(4) = 88. \nFind
<var>f</var>(10).\n\n"