1555153domain: NPropertiesPrimalityPrimeyesAppears in sequencesExpansion of (1-x) * (1+x) / ((1-2*x)*(1-x-x^2)).at n=19A104004a(n) = numerator of sum{k=1 to n} 1/A127515(k).at n=14A127516Prime numbersat n=118018