-1865domain: ZAppears in sequencesValues of n such that L(17) and N(17) are both prime, where L(k) = (n^2+n+1)*2^(2*k) + (2*n+1)*2^k + 1, N(k) = (n^2+n+1)*2^k + n.at n=17A227520Expansion of Product_{k>=1} (1 - x^(2*k-1))^(2*k-1).at n=21A285069Expansion of Product_{k>=2} (1 - x^k)^k.at n=31A298599