# A000636 (b-file synthesized from sequence entry) 1 1 2 2 3 4 4 9 5 21 6 52 7 129 8 332 9 859 10 2261 11 5983 12 15976 13 42836 14 115469 15 312246 16 847241 17 2304522 18 6283327 19 17164401 20 46972357 21 128741107 22 353345434 23 970999198 24 2671347292 25 7356752678 26 20279171785 27 55948407837 28 154479213626 29 426845422807 30 1180229767202