110297domain: NAppears in sequencesThe number of rectangles (orthogonal or not) with corners on an n X n grid of points.at n=21A085582Number of compositions of n into parts of sizes == 1 mod 5 or 4 mod 5.at n=30A116975Numbers k not divisible by 3 such that no prime is the concatenation of two numbers whose sum is n.at n=2A375938