# A058818 (b-file synthesized from sequence entry) 0 1 1 3 2 6 3 19 4 63 5 195 6 613 7 1875 8 5751 9 17499 10 53169 11 161043 12 487221 13 1471683 14 4441485 15 13392331 16 40356711 17 121543683 18 365898261 19 1101089811 20 3312448137 21 9962241251 22 29954655861 23 90049997139 24 270661661541 25 813397065075 26 2444101819329 27 7343167949235