Comment (by Barry Wardell):

The Black Hole Perturbation Toolkit has a similar repository within the context of pN expansions in the large mass ratio regime. The Post-Newtonian Self-force package is a Mathematica interface to the repository, but there is a desire within the community to have something which is tool-agnostic. There have also been discussions about extending the scope to cover more generic post-Newtonian series. It might make sense to coordinate those efforts with this one.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2417/include-pn-expressions-for-initial-momenta