78678domain: NAppears in sequencesIntegers n > 1 such that A130280(4n^2) < n, i.e., there is an m < n, m > 1 such that 4n^2(m^2 - 1) + 1 is a square.at n=31A130281Number of 2-matchings of the n-th centered square grid graph.at n=10A344679