# A337591 (b-file synthesized from sequence entry) 0 1 1 1 2 6 3 51 4 760 5 15545 6 428256 7 15043483 8 653049664 9 34204348305 10 2118834917200 11 152834879685851 12 12670536337934256 13 1194143629239156505 14 126753440317516749660 15 15031687739886065433375 16 1977667235694725269563136 17 286890421090357737699794209 18 45637300134026406622214264592