The infinite sequence \(S=\{s_1,s_2,s_3,\ldots\}\) is defined by \(s_1=7\) and \(s_n=7^{s_{n-1}}\) for each integer \(n>1\) . What is the remainder when \(s_{100}\) is divided by \(5\) ?
The remainder when $s_{100}$ is divided by 5 is 4.
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