# A149837 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 12 4 36 5 100 6 324 7 1052 8 3228 9 10852 10 36532 11 117676 12 404364 13 1390516 14 4610980 15 16077660 16 56078812 17 189603652 18 668095892 19 2354323852 20 8071935148 21 28669742292 22 101819683204 23 352800887100 24 1260929362940 25 4505714683748 26 15742066776692 27 56548206097260 28 203073342063308 29 714263158415348 30 2576510962881380