# A235321 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 10 4 56 5 496 6 4592 7 58240 8 753536 9 12428416 10 206700032 11 4194910720 12 85291222016 13 2054623707136 14 49390297628672 15 1376983620812800 16 38210541166493696 17 1209980100295622656 18 38070418025153626112 19 1349585751030491054080 20 47479274652991633227776