1667837680domain: NAppears in sequencesNumber of ways of writing 0 as Sum_{k=-n..n} e(k)*k, where e(k) is 0 or 1.at n=18A000980Number of nX1 0..1 arrays with every row and column least squares fitting to a zero slope straight line, with a single point array taken as having zero slope.at n=36A222955