IMO Shortlist 1981 problem 7
Dodao/la:
arhiva2. travnja 2012. The function
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satisfies:
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for all non-negative integers
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. Find
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.
%V0
The function $f(x,y)$ satisfies: $f(0,y)=y+1, f(x+1,0) = f(x,1), f(x+1,y+1)=f(x,f(x+1,y))$ for all non-negative integers $x,y$. Find $f(4,1981)$.
Izvor: Međunarodna matematička olimpijada, shortlist 1981