We prove that a two-variable -adic -function has the series expansion which interpolates the values , whenever is a nonpositive integer. The proof of this original construction is due to Kubota and Leopoldt in 1964, although the method given in this note is due to Washington.
"On a Two-Variable -Adic -Function." Abstr. Appl. Anal. 2008 1 - 10, 2008. https://doi.org/10.1155/2008/360517