# A177615 (b-file synthesized from sequence entry) 0 1 1 1 2 20 3 1680 4 369600 5 168168000 6 137127810959 7 182138398520387 8 367988956112888200 9 1074073326771101149080 10 4350318942513425384777400 11 23673963203663687592089088600 12 168569155472096397352266896207243 13 1536148007688582239667327040442799059