# A126488 (b-file synthesized from sequence entry) 0 1 1 20 2 128 3 840 4 5560 5 36988 6 246840 7 1650808 8 11056590 9 74130748 10 497387482 11 3339002940 12 22423219250 13 150623072388 14 1011962290858 15 6799752144942 16 45694220498130 17 307084056184964 18 2063824981953422 19 13870824556736138