3113860domain: NAppears in sequencesNumber of perfect matchings in the graph C_6 x C_n.at n=5A232804Number of perfect matchings in the graph C_8 X C_n.at n=3A253678Square array T(n,k), n >= 1, k >= 1, read by antidiagonals downwards: number of perfect matchings in the graph C_{2n} x C_k.at n=39A341741