Let p n p_n be the n n th prime number. In 2000, Papaitopol proved that the inequality p 1 ⋯ p n > p n + 1 n − π ( n ) p_1\cdots p_n>p_{n+1}^{n-\pi (n)} holds, for all n ≥ 2 n\geq 2 , where π ( x ) \pi (x) is the prime counting function. In 2021, Yang and Liao tried to sharpen this inequality by replacing n − π ( n ) n-\pi (n) by n − π ( n ) + π ( n ) / π ( log n ) − 2 π ( π ( n ) ) n-\pi (n)+\pi (n)/\pi (\log n)-2\pi (\pi (n)) , however there is a small mistake in their argument. In this paper, we exploit properties of the logarithm error term in inequalities of the type p 1 ⋯ p n > p n + 1 k ( n , x ) p_1\cdots p_n>p_{n+1}^{k(n,x)} , where k ( n , x ) = n − π ( n ) + π ( n ) / π ( log n ) − x π ( π ( n ) ) k(n,x)=n-\pi (n)+\pi (n)/\pi (\log n)-x\pi (\pi (n)) . In particular, we improve Yang and Liao estimate, by showing that the previous inequality at x = 1.4 x=1.4 holds for all n ≥ 21 n\geq 21 .
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