# A357661 (b-file synthesized from sequence entry) 0 1 1 0 2 2 3 12 4 60 5 320 6 2040 7 15568 8 133648 9 1230336 10 11962400 11 123144384 12 1349008320 13 15731096576 14 194349866880 15 2527082917120 16 34392647418112 17 488243791183872 18 7216792525799936 19 110936087161801728 20 1771199461131500544 21 29324602146652307456