https://en.wikipedia.org/wiki/Indefinite_sum https://codeberg.org/AzulBeae/norlundcalc similar to this https://www.desmos.com/calculator/anih6sjvmb?backgroundColor=bbb&textColor=235656&invertedColors inverse backward difference sum https://www.desmos.com/calculator/it2cyev2j8?backgroundColor=bbb&textColor=235656&invertedColors product version it'd be for things like this https://arxiv.org/pdf/0710.5539
https://en.wikipedia.org/wiki/Indefinite_sum
https://codeberg.org/AzulBeae/norlundcalc similar to this
https://www.desmos.com/calculator/anih6sjvmb?backgroundColor=bbb&textColor=235656&invertedColors inverse backward difference sum
https://www.desmos.com/calculator/it2cyev2j8?backgroundColor=bbb&textColor=235656&invertedColors product version
it'd be for things like this https://arxiv.org/pdf/0710.5539