We show that if the first case of Fermat's Last Theorem is false for prime exponent \( p\) then \(p^2\) divides \( q^p-q\) for all primes \( q\leq 89\). The title theorem follows.
We prove that for any odd \( n>1\) and sufficiently large \( m\) there exists a nested Steiner \(n\)-cycle system of order \( m\) if and only of \( m\equiv 1 \pmod {2n}\).
For which integers \( s,t, n=2st\) does there exist a decomposition of the complete graph on \( n\) vertices into \( n-1\) copies of the complete \( (s,t)\)-bipartite graph?