# A288720 (b-file synthesized from sequence entry) 0 0 1 1 2 16 3 184 4 1744 5 15136 6 126016 7 1028224 8 8306944 9 66781696 10 535561216 11 4289726464 12 34338770944 13 274794029056 14 2198687727616 15 17590843899904 16 140732119711744 17 1125878432137216 18 9007113355657216 19 72057250441068544 20 576459377914937344