178322domain: NAppears in sequencesa(n) = 6*binomial(n,4) + 3*binomial(n,3) + 4*binomial(n,2) - n + 2.at n=29A066375(1/4) * number of ways to select 3 distinct points forming a triangle of unsigned area = n/2 from a square of grid points with side length n.at n=27A320310