161518domain: NAppears in sequencesNumber of permutations of length n which avoid the patterns 2134, 3421, 4123.at n=17A116759Number of nX4 0..1 arrays with every element unequal to 0, 1, 2 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=12A318071