Inequalities for the Euler-Mascheroni constant

Let Rn = n k=1 1 k −log n + 1 2 , H(n) = n 2 (Rn −γ), n = 1, 2,. . ., where γ is the Euler-Mascheroni constant. We prove that for all integers n ≥ 1, H(n) and [(n + 1/2)/n] 2 H(n) are strictly increasing, while [(n + 1)/n] 2 H(n) is strictly decreasing. For all integers n ≥ 1, 1 24(n + a) 2 ≤ Rn − γ < 1 24(n + b) 2 with the best possible constants a = 1 24[−γ + 1 − log(3/2)] − 1 = 0.55106. .. and b = 1 2. This refines result of D. W. DeTemple, who proved that the double inequality holds with a = 1 and b = 0.