# A048457 (b-file synthesized from sequence entry) 1 7 2 23 3 67 4 179 5 453 6 1109 7 2653 8 6231 9 14409 10 32877 11 74137 12 165429 13 365691 14 801747 15 1745331 16 3776605 17 8130401 18 17427659 19 37217597 20 79224121 21 168170537 22 356107787 23 752453861 24 1586875049 25 3340696135 26 7021048691 27 14731810645