# A025234 (b-file synthesized from sequence entry) 0 1 1 0 2 4 3 8 4 28 5 83 6 255 7 778 8 2377 9 7259 10 22173 11 67721 12 206844 13 631764 14 1929609 15 5893632 16 18001012 17 54980764 18 167928588 19 512906847 20 1566579211 21 4784826786 22 14614369465 23 44636891651 24 136335139273 25 416410496177 26 1271848932360 27 3884627600872 28 11864877355729