# A007162 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 7 4 24 5 96 6 388 7 1667 8 7278 9 32726 10 149232 11 692014 12 3244182 13 15374906 14 73474008 15 353835147 16 1714967402 17 8360511370 18 40964207460 19 201630767026 20 996494168808 21 4943036743112 22 24601517883704 23 122815436413582 24 614828204108840