Stage: 5 Challenge Level: 
Show that $3^{(3n+4)}+7^{(2n+1)}$ is a multiple of 11 for all positive integer values of $n$.
Index notation/Indices. Number theory. Divisibility. Modulus arithmetic. Binomial Theorem. Mathematical reasoning & proof. epsilons. Mathematical induction. Fibonacci sequence. Long problems.
Published March 2007,April 2007.
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