# A084729 (b-file synthesized from sequence entry) 1 2 2 3 3 7 4 73 5 1801 6 21601 7 151201 8 8467201 9 304819201 10 18289152001 11 201180672001 12 4828336128001 13 502146957312001 14 56240459218944001 15 12654103324262400001 16 1417259572317388800001 17 144560476376373657600001