# A355294 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 14 4 88 5 670 6 6170 7 66360 8 815640 9 11272800 10 173132400 11 2925014400 12 53909394000 13 1076365290000 14 23144112591600 15 533193460800000 16 13102608591072000 17 342105146182800000 18 9457689380931792000 19 275988880808825184000 20 8477631163592791200000 21 273430368958004818560000 22 9238944655686318693120000