38263753domain: NAppears in sequencesPierpont 4-almost primes: numbers with exactly 4 prime divisors, not necessarily distinct, of the form 2^K*3^L + 1.at n=24A111344a(n) = 8*3^n + 1.at n=14A199111a(n) = 8*9^n+1.at n=7A199677