# A337905 (b-file synthesized from sequence entry) 1 1 2 2 3 15 4 60 5 340 6 1680 7 9135 8 48440 9 264726 10 1446060 11 7996296 12 44396352 13 248133600 14 1392623232 15 7850732175 16 44413669872 17 252098234674 18 1435074678180 19 8190821465970 20 46860693370920 21 268676908816680 22 1543504863288960 23 8883248453674920 24 51210412534906560