# A097346 (b-file synthesized from sequence entry) 0 1 1 2 2 9 3 24 4 170 5 240 6 2415 7 7000 8 30744 9 45360 10 741510 11 1108800 12 21673080 13 32744712 14 49684635 15 151351200 16 3932288360 17 6028102080 18 176061013128 19 271314186000 20 419047770960 21 648560072160 22 23130491854470 23 35929017476352