# A368048 (b-file synthesized from sequence entry) 0 1 1 3 2 36 3 540 4 6480 5 136080 6 8164800 7 24494400 8 293932800 9 48498912000 10 4073908608000 11 158882435712000 12 9532946142720000 13 28598838428160000 14 343186061137920000 15 612587119131187200000 16 7351045429574246400000 17 419009589485732044800000 18 276546329060583149568000000