# A148781 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 8 4 23 5 81 6 280 7 977 8 3604 9 13639 10 52495 11 204309 12 809815 13 3254081 14 13151968 15 53676309 16 221332075 17 919068872 18 3840205474 19 16141523490 20 68250278556 21 290038761654 22 1237578756865 23 5303354547855 24 22822808433377 25 98575512487716 26 427174939588696 27 1857042440689138 28 8097662637790062