75494983297domain: NAppears in sequencesNumber of alignments of n strings of length 7.at n=3A062204Number of paths from (0,0,0) to (n,n,n) such that at each step (i) at least one coordinate increases, (ii) no coordinate decreases, (iii) no coordinate increases by more than 1 and (iv) all coordinates are integers.at n=7A126086