# A148210 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 4 4 12 5 36 6 121 7 418 8 1518 9 5680 10 21838 11 85728 12 342817 13 1391551 14 5723767 15 23807834 16 100015361 17 423803675 18 1809693470 19 7780676837 20 33658840612 21 146415125415 22 640107365528 23 2811273477261 24 12398413335191 25 54889792298990 26 243863779060244 27 1086965933597889 28 4859517276156715