14601604domain: NAppears in sequencesNumber of perfect matchings on a Möbius strip of width 3 and length 2n.at n=10A263200a(n) = ((1 - sqrt(3))^n + (1 + sqrt(3))^n)/2^floor((n - 1)/2); n-th row common denominator of A321118.at n=24A321119