# A148572 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 6 4 19 5 54 6 183 7 632 8 2307 9 8753 10 34000 11 135893 12 552498 13 2288861 14 9619432 15 40955833 16 176439889 17 767614597 18 3370686080 19 14919375855 20 66519132927 21 298537169659 22 1347748022530 23 6117531357164 24 27904394951401 25 127858017889598 26 588274930715447 27 2716966368936216 28 12592645826466517