# A000628 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 1 4 2 5 3 6 5 7 11 8 24 9 55 10 136 11 345 12 900 13 2412 14 6563 15 18127 16 50699 17 143255 18 408429 19 1173770 20 3396844 21 9892302 22 28972080 23 85289390 24 252260276 25 749329719 26 2234695030 27 6688893605 28 20089296554 29 60526543480 30 182896187256 31 554188210352 32 1683557607211 33 5126819371356 34 15647855317080 35 47862049187447 36 146691564302648 37 450451875783866 38 1385724615285949