# A209230 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 5 4 13 5 34 6 88 7 226 8 578 9 1476 10 3768 11 9620 12 24564 13 62728 14 160192 15 409096 16 1044744 17 2668048 18 6813600 19 17400400 20 44436688 21 113481248 22 289805440 23 740097568 24 1890041888 25 4826739776 26 12326402432