93050domain: NAppears in sequencesFloor of the area of consecutive Prime-Indexed Prime triangles.at n=19A119659Number of (w,x,y,z) with all terms in {1,...,n} and w<|x-y|+|y-z|.at n=20A212568a(n) = Sum_{k=1..n} mu(k)*k^5.at n=13A336279