# A025249 (b-file synthesized from sequence entry) 1 1 2 1 3 3 4 7 5 13 6 29 7 71 8 163 9 377 10 913 11 2219 12 5375 13 13189 14 32677 15 81167 16 202523 17 508273 18 1280537 19 3236275 20 8207543 21 20880893 22 53263405 23 136205527 24 349137811 25 896881641 26 2308523809 27 5953138875 28 15378562415 29 39791453685 30 103115768885 31 267597960095