# A119581 (b-file synthesized from sequence entry) 0 0 1 3 2 24 3 150 4 840 5 4410 6 22176 7 108108 8 514800 9 2406690 10 11085360 11 50438388 12 227149104 13 1014058500 14 4493059200 15 19777483800 16 86555576160 17 376877404530 18 1633524354000 19 7051380128100 20 30326236340400 21 129989276677260 22 555482126422080 23 2367111334185000 24 10061252349127200