47971603domain: NAppears in sequencesNumber T(n,k) of tilings of a 5 X n rectangle with pentominoes of any shape and exactly k pentominoes of shape X; triangle T(n,k), n>=0, read by rows.at n=29A247711Number of tilings of a 5 X n rectangle using n pentominoes of any shape including exactly one X shape.at n=11A247828