# A097121 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 1 4 5 5 17 6 41 7 81 8 157 9 337 10 785 11 1825 12 4085 13 8913 14 19449 15 42993 16 95885 17 213777 18 474465 19 1049921 20 2323685 21 5150865 22 11429321 23 25358737 24 56233853 25 124658129 26 276348849 27 612740961 28 1358769877 29 3013068113 30 6681031065 31 14813622577