# A097786 (b-file synthesized from sequence entry) 0 1 1 7 2 31 3 113 4 374 5 1178 6 3618 7 10974 8 33087 9 99481 10 298729 11 896551 12 2690108 13 8070884 14 24213332 15 72640812 16 217923405 17 653771355 18 1961315395 19 5883947725 20 17651844946 21 52955536862 22 158866612886 23 476599841258 24 1429799526699