IMO Shortlist 1987 problem 14
Dodao/la:
arhiva2. travnja 2012. How many words with
digits can be formed from the alphabet
, if neighboring digits must differ by exactly one?
Proposed by Germany, FR.
%V0
How many words with $n$ digits can be formed from the alphabet $\{0, 1, 2, 3, 4\}$, if neighboring digits must differ by exactly one?
Proposed by Germany, FR.
Izvor: Međunarodna matematička olimpijada, shortlist 1987