Problem 12 IMC 2004 Macedonia
Source:
July 26, 2004
linear algebramatrixIMCcollege contests
Problem Statement
For define the matrices and as follows: A_0 \equal{} B_0 \equal{} (1), and for every let
A_n \equal{} \left( \begin{array}{cc} A_{n \minus{} 1} & A_{n \minus{} 1} \\
A_{n \minus{} 1} & B_{n \minus{} 1} \\
\end{array} \right) \ \textrm{and} \ B_n \equal{} \left( \begin{array}{cc} A_{n \minus{} 1} & A_{n \minus{} 1} \\
A_{n \minus{} 1} & 0 \\
\end{array} \right).
Denote by the sum of all the elements of a matrix . Prove that S(A_n^{k \minus{} 1}) \equal{} S(A_k^{n \minus{} 1}), for all .