531121domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumbers k such that k, k+1, k+2, k+3 and k+4 are respectively 1,2,3,4,5-almost primes.at n=9A113008a(n) = 1681*n^2 - 756*n + 85.at n=17A157010Prime numbersat n=43913