8999307domain: 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 T; triangle T(n,k), n>=0, 0<=k<=max(0,floor(2*(n-1)/3)), read by rows.at n=25A247707Number of tilings of a 5 X n rectangle using n pentominoes of any but the T shape.at n=9A247771