# A149930 (b-file synthesized from sequence entry) 0 1 1 2 2 5 3 15 4 48 5 171 6 637 7 2428 8 9550 9 38349 10 156705 11 650514 12 2730685 13 11586035 14 49633476 15 214245357 16 931290307 17 4073517547 18 17914555800 19 79177186936 20 351493613879 21 1566615341461 22 7008105335834 23 31454517640160 24 141606919092096 25 639300738693485 26 2893656057013955 27 13128807209968934