Palindromic Compositions
A composition of n is an ordered sum of positive integers equal to n, such as 3 + 1 + 4 for 8. A composition is palindromic if its sequence of parts reads the same forwards and backwards (for example 2 + 5 + 5 + 2 or 3 + 14 + 3, or the one-part composition 20). How many palindromic compositions of 20 are there? Give an integer.
Related problems & prerequisites
Worth solving first
- Digits That Never Decrease 4.0/10
- Lucky Tram Tickets 4.0/10
- Four Identical Dice 4.0/10
Source: Classic exercise in wide circulation; no traceable original source. Statement written for AxiomIQ.