# A119917 (b-file synthesized from sequence entry) 1 1 2 3 3 9 4 21 5 51 6 105 7 231 8 471 9 975 10 1965 11 4011 12 8031 13 16221 14 32475 15 65205 16 130485 17 261555 18 523131 19 1047417 20 2094957 21 4191975 22 8384229 23 16772835 24 33545715 25 67100115 26 134200785 27 268418001 28 536837061 29 1073707971 30 2147415981