# A026153 (b-file synthesized from sequence entry) 2 1 3 2 4 7 5 20 6 60 7 176 8 517 9 1512 10 4415 11 12870 12 37477 13 109044 14 317109 15 921870 16 2679510 17 7787904 18 22636503 19 65804638 20 191332945 21 556456060 22 1618813834 23 4710869108 24 13713658368 25 39935698400 26 116340344575 27 339050396646 28 988474306017