46490458680domain: NAppears in sequencesNumber of transpositions (interchanges of adjacent digits, sometimes called inversions) needed to change all n-digit base 3 numbers into nondecreasing order.at n=18A069515a(n) = 2*n*3^(n-1).at n=19A212697Numbers k in A055932 such that both k-1 and k+1 are not squarefree.at n=18A386527