25625600domain: NAppears in sequencesNumber T(n,k) of permutations on n elements with exactly k 3-cycles; triangle read by rows.at n=38A186526Numerator of n!/3^n.at n=13A212307T(n, k) = (3^(-k)*n!*2^(n - 3*k))/(k!*(n - 3*k)!), for n >= 0 and 0 <= k <= floor(n/3). Triangle read by rows.at n=38A344915