# A027235 (b-file synthesized from sequence entry) 0 1 1 3 2 8 3 22 4 53 5 138 6 317 7 803 8 1794 9 4478 10 9823 11 24321 12 52662 13 129815 14 278365 15 684689 16 1457113 17 3581074 18 7574863 19 18616678 20 39182980 21 96351078 22 201947877 23 497006898 24 1038017513 25 2557192089 26 5324505911 27 13131212951 28 27268815916