485041domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 55.at n=20A031643Numerators of the partial sums of the Möbius transform of the harmonic numbers.at n=13A334314Prime numbersat n=40385