We provide a set of optimal estimates of the form (1-μ)/𝓐(x,y) + μ/ℳ (x,y) ≤ 1/ℬ(x,y) ≤ (1-ν)/𝓐(x,y) + ν/ℳ (x,y) where 𝓐 < ℬ are two of the Seiffert means L,P,M,T, while ℳ is another mean greater than the two.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm130-2-8, author = {Alfred Witkowski}, title = {Optimal weighted harmonic interpolations between Seiffert means}, journal = {Colloquium Mathematicae}, volume = {131}, year = {2013}, pages = {265-279}, zbl = {1276.26062}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm130-2-8} }
Alfred Witkowski. Optimal weighted harmonic interpolations between Seiffert means. Colloquium Mathematicae, Tome 131 (2013) pp. 265-279. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm130-2-8/