72580domain: NAppears in sequencesNumbers k for which phi(k) = phi(k+1) - phi(k-1).at n=29A076529A007318^2 * A007248.at n=11A134443Number of (w,x,y,z) with all terms in {1,...,n} and median<mean.at n=20A212135Numbers k such that A075255(k) is the square of a prime.at n=42A386954