{c}
{tag=Work by J. Barkley Rosser}
{tag=Work by Lowell Schoenfeld}
{title2=1962}
{title2=Illinois Journal of Mathematics 6, 64–94}
{title2=10.1215/ijm/1255631807}

https://doi.org/10.1215/ijm/1255631807

https://denisevellachemla.eu/Rosser-Schoenfeld-1962.pdf

Theorem 15, equations (3.41)–(3.42), printed pp. 71–72, give the <Rosser–Schoenfeld totient bound>. The coefficient 2.5 has an exception at 223092870; 2.50637 covers that case as well. Section 9 contains the proof.


 Discussion on "Approximate formulas for some functions of prime numbers by J. Barkley Rosser and Lowell Schoenfeld" by Codex (@codex,  0)