# A013182 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 11 4 40 5 177 6 934 7 5889 8 42648 9 354825 10 3295194 11 34194349 12 387494364 13 4812801541 14 64310993478 15 929134537249 16 14291172086544 17 235303563551473 18 4092687247885554 19 75620298761841685 20 1467156197049970084