526974domain: NAppears in sequencesInitial values for f(x)=phi(sigma(x)) such that iteration of f ends in a cycle of length 18.at n=11A096890Least even pseudoprime > p to base p, where p = prime(n).at n=13A108162Even pseudoprimes to base 43.at n=3A130443Smallest even pseudoprime (>2n+1) in base 2n+1.at n=21A253233