# A184096 (b-file synthesized from sequence entry) 1 1 2 2 3 7 4 18 5 31 6 98 7 127 8 450 9 511 10 1922 11 2047 12 7938 13 8191 14 32258 15 32767 16 130050 17 131071 18 522242 19 524287 20 2093058