<p>Fibonacci numbers mod 5 would be interesting 
except that every fifth Fibonacci number is 0 mod 5.</p>
<p>This reminds me of the 2012 AMC12A, where the answers to #22 through #25 were all C.</p>
<p>Fibonacci numbers mod 5 would be interesting except that every fifth Fibonacci number is 0 mod 5.</p>
<p>This reminds me of the 2012 AMC12A, where the answers to #22 through #25 were all C.</p>