# A004367 (b-file synthesized from sequence entry) 12 1 13 78 14 3486 15 117480 16 3321960 17 83291670 18 1913554188 19 41146859952 20 840261910995 21 16466440817750 22 312058705015200 23 5752562036128128 24 103619293824707388 25 1830311583210984300 26 31794836537065001400