44981domain: NAppears in sequencesa(n)=(-1)^n(1 - (1/12)n(n + 1)(12 - n + n^2)).at n=27A080275Number of n X 2 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.at n=29A252814