# A316766 (b-file synthesized from sequence entry) 1 1 2 1 3 2 4 3 5 6 6 13 7 30 8 72 9 180 10 458 11 1194 12 3160 13 8459 14 22881 15 62417 16 171526 17 474405 18 1319395 19 3687711 20 10352696 21 29178988