# A277247 (b-file synthesized from sequence entry) 0 1 1 1 2 5 3 10 4 53 5 126 6 662 7 1716 8 8885 9 24310 10 124130 11 352716 12 1778966 13 5200300 14 25947612 15 77558760 16 383358645 17 1166803110 18 5719519850 19 17672631900 20 85990654178 21 269128937220 22 1300866635172 23 4116715363800 24 19780031677718 25 63205303218876 26 302045506654052