# A015759 (b-file synthesized from sequence entry) 1 1 2 2 3 3 4 6 5 22 6 33 7 66 8 750 9 27798250 10 41697375 11 76745867 12 83394750 13 153491734 14 207656250 15 230237601 16 460475202 17 917342250 18 969062500 19 2907187500 20 4528006153 21 5952812500 22 9056012306 23 13584018459 24 17858437500 25 27168036918 26 31979062500 27 57559400250