Euler E704: Further investigation of series progressing by multiples of an angle | English translation | OMH v1.0

English translation of Leonhard Euler's E704, Further investigation of series progressing by multiples of an angle. AI use and review status: OpenAI tools assisted with the translation and LaTeX. Version 1.0 is a machine draft with limited scholarly human inspection. Version 2.0 is reserved for a fully reviewed edition. Sources: Official Euler Archive record E704, https://scholarlycommons.pacific.edu/euler-works/704/ ; consulted original volume, Nova Acta Academiae Scientiarum Imperialis Petropolitanae XI (1798), pp. 114–132, https://archive.org/details/novaactaacademia11petr ; Natural History Museum Library, London, exact BHL item 113775, https://www.biodiversitylibrary.org/item/113775 .