Asymptotic expansions for the Wallis sequence and some new mathematical constants associated with the Glaisher-Kinkelin and Choi-Srivastava constants

The celebrated Wallis sequence Wn, which is defined by Wn := ?nk=1 4k2/4k2?1, known to have the limit ? 2 as n ?. Without using Bernoulli numbers Bn, authors present several asymptotic expansions and a recurrence relation for determining coefficients of each expansion related newly-introduced constants D E, are analogous Glaisher-Kinkelin constant A Choi-Srivastava B C.