# A004729 (b-file synthesized from sequence entry) 0 1 1 3 2 5 3 15 4 17 5 51 6 85 7 255 8 257 9 771 10 1285 11 3855 12 4369 13 13107 14 21845 15 65535 16 65537 17 196611 18 327685 19 983055 20 1114129 21 3342387 22 5570645 23 16711935 24 16843009 25 50529027 26 84215045 27 252645135 28 286331153 29 858993459 30 1431655765 31 4294967295