This is a Literate Haskell module with functions to enumerate the elements of the Eisenstein array. Also, we provide a program that searches for occurrences of the Eisenstein array on OEIS. (Joint work with Roland Backhouse.)
I suggest that you read the PDF version of the Literate Haskell program.
In 1858, A.M. Stern published a detailed study of a process of constructing an infinite sequence of numbers from a given pair of numbers. Stern attributed the process to Eisenstein, and the sequence of numbers is now known as the Eisenstein array.
In a recent paper [0], we review Stern's paper and briefly discuss algorithms that enumerate the elements of the Eisenstein Array. In this document we present several Haskell implementations of these algorithms.
[0] Roland C. Backhouse and João F. Ferreira. On Euclid's algorithm and elementary number theory. Sci. Comput. Program. (76:3), 2011. URL: http://joaoff.com/publications/2010/euclid-alg/