# A053548 (b-file synthesized from sequence entry) 1 1 2 0 3 0 4 2 5 4 6 9 7 32 8 90 9 240 10 654 11 1804 12 4950 13 13664 14 37944 15 106272 16 298890 17 843796 18 2390595 19 6796160 20 19370696 21 55345680 22 158489298 23 454803100 24 1307556162 25 3765741324 26 10862667648 27 31381058880 28 90780903460 29 262951527460