# A201969 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 6 4 16 5 52 6 169 7 556 8 1902 9 6667 10 23665 11 85062 12 309444 13 1136400 14 4205944 15 15675690 16 58785582 17 221644054 18 839692735 19 3194875093 20 12203132521 21 46774765206 22 179861164503 23 693632630011 24 2682150035748 25 10396942423617 26 40393878209664 27 157267923352012 28 613499893576207