1039500domain: NAppears in sequencesNumber of factorizations of m^n into exactly four factors, where m is a product of two distinct primes.at n=29A277240T(n, k) = (1/n) * Sum_{d|n} phi(d) * A241171(n/d, k) for n >= 1, T(0, k) = 0^k. Triangle read by rows for 0 <= k <= n.at n=26A327027