1164375domain: NAppears in sequencesn and n+9 are 9-almost primes.at n=8A124946a(n) = H(n-1, n, n+1) where H(a, b, c) = (a + b + c)*(a + b - c)*(b + c - a)*(c + a - b) is Heron's polynomial.at n=25A339488Odd numbers k such that A000045(k)/A000005(k) is an integer.at n=11A377032