# A158900 (b-file synthesized from sequence entry) 0 1 1 1 2 4 3 20 4 116 5 756 6 5448 7 43032 8 370704 9 3472656 10 35303424 11 388786176 12 4628774016 13 59431077504 14 820503839232 15 12140411779584 16 191844739736064 17 3226219598338560 18 57540789020021760 19 1084906603389864960