# A068552 (b-file synthesized from sequence entry) 0 -1 1 0 2 8 3 56 4 304 5 1496 6 6992 7 31664 8 140384 9 613016 10 2646544 11 11325200 12 48122528 13 203306736 14 854829344 15 3579783776 16 14939605184 17 62162742296 18 257985394064 19 1068242117456 20 4414349525024 21 18208784215376 22 74988168359264 23 308369069291936