No Consecutive Elements
How many subsets of {1, 2, ..., 10} (including the empty set) contain no two consecutive integers?
Related problems & prerequisites
Worth solving first
- Tiling with Dominoes 3.0/10
- Counting Surjections 2.6/10
Source: Standard Fibonacci-flavoured subset-counting exercise from combinatorics texts. Statement written for AxiomIQ.