# A336419 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 10 4 24 5 64 6 184 7 536 8 1608 9 5104 10 16448 11 55136 12 187136 13 658624 14 2339648 15 8618208 16 31884640 17 121733120 18 468209408 19 1849540416 20 7342849216