# A024959 (b-file synthesized from sequence entry) 1 2 2 1 3 2 4 4 5 8 6 20 7 48 8 112 9 264 10 688 11 1760 12 4432 13 11136 14 30208 15 80160 16 209344 17 547584 18 1498752 19 4052224 20 10840064 21 28972416 22 80315136 23 220124160 24 597656576 25 1623036928 26 4522262528 27 12503194624 28 34330329088 29 94172397568 30 264205592576 31 735690285056