# A055156 (b-file synthesized from sequence entry) 0 3 1 9 2 81 3 243 4 2187 5 6561 6 59049 7 177147 8 1594323 9 4782969 10 43046721 11 129140163 12 1162261467 13 3486784401 14 31381059609 15 94143178827 16 847288609443 17 2541865828329 18 22876792454961 19 68630377364883 20 617673396283947