# A027763 (b-file synthesized from sequence entry) 1 2 2 3 3 5 4 11 5 23 6 47 7 283 8 719 9 1439 10 2879 11 34549 12 138197 13 531441 14 1594323 15 4782969 16 14348907 17 43046721 18 86093443 19 344373773 20 688747547 21 3486784401