# A320424 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 2 4 4 5 13 6 31 7 140 8 480 9 2306 10 9179 11 58209 12 249205 13 1802970 14 9463155 15 63813439 16 389176317 17 3415876088 18 20506436732 19 195865505549 20 1353967583125 21 12006363947433 22 93067012435816 23 1019489483393439