135762domain: NAppears in sequencesa(0) = 1, a(1) = 1 and for n >= 2, a(n) = floor(4 * a(n-2) * a(n-1) / (a(n-2) + a(n-1))).at n=28A093335Number of (w,x,y,z) with all terms in {1,...,n} and w<2x and y<=2z.at n=22A212507G.f. A(x) satisfies A(x) = 1 + x*abs( 1/A(x) )^3.at n=14A380709