# A218873 (b-file synthesized from sequence entry) 1 1 2 1 3 2 4 3 5 20 6 168 7 25740 8 1627920 9 7600186994400 10 91351145008363640400 11 41220780807793167133364240240011200 12 86885947737342403570395603462501113422055643279216000