274844352512domain: NAppears in sequencesNumbers whose binary representation is the concatenation of n 1's and 2n-1 digits 0.at n=12A147538Near-perfect numbers (A181595) of the form m*2^p, where m = 2^(p-1)*(2^p-1) is a perfect number (A000396).at n=4A181710Expansion of 1/((1-4*x^2)^(3/2)-2*x*(1-4*x^2)).at n=25A270822