# A013990 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 16 4 800 5 323632 6 1086297184 7 30766606427588 8 7466577706821521924 9 15681997226277809235573754 10 286995508313697459220070082104780 11 45988915870193885369543805313062149050276