# A176476 (b-file synthesized from sequence entry) 0 0 1 1 2 6 3 27 4 113 5 464 6 1896 7 7738 8 31571 9 128800 10 525455 11 2143647 12 8745216 13 35676948 14 145547524 15 593775045 16 2422362078 17 9882257735 18 40315615409 19 164471408184 20 670976837020 21 2737314167774 22 11167134898975 23 45557394660800 24 185855747875875 25 758216295635151