# A149336 (b-file synthesized from sequence entry) 0 1 1 1 2 4 3 12 4 40 5 147 6 552 7 2108 8 8316 9 33289 10 134841 11 553959 12 2298348 13 9612184 14 40539298 15 172119016 16 735000952 17 3156525934 18 13621846126 19 59039338928 20 256950972772 21 1122435218403 22 4919640466189 23 21631898475941 24 95393882536337 25 421809165548347 26 1869910737898759 27 8309058724349230