# A151284 (b-file synthesized from sequence entry) 0 1 1 2 2 6 3 20 4 70 5 254 6 942 7 3550 8 13532 9 52030 10 201386 11 783560 12 3061442 13 12001804 14 47181278 15 185904220 16 733908634 17 2901998092 18 11490757796 19 45552262860 20 180762964146 21 717939220774 22 2853611232902 23 11349816190552 24 45168339253888 25 179845805435900 26 716409551285034 27 2854926106932244