The following details have been related by Ed Sandifer:
On November 19, 1773, the Academy had its meeting to pick the articles to publish in the Mathematics section of the next volume of the Novi Commentarii. They picked eight articles by Euler, E-445 and E-448 to E-454. Three days later, they received two articles from Daniel Bernoulli in Basel, one of which was very closely related to one of Euler's articles, not on the list (E-447) about sums of sines of angles that are in geometric progression. They decided to publish that one right next to Euler's article, but that made the Mathematics section of that volume too big. So, Euler volunteered to withdraw one of his articles. He picked E-445 and sent it to the Acta Eruditorum instead.

Publication:

• Originally published in Acta Eruditorum 1777, 1780, pp. 48-69
• Opera Omnia: Series 1, Volume 3, pp. 218 - 238
• Reprinted in Acta. acad. sc. Petrop. 1777: II, printed 1780, pp. 48-69 [E445a]
• Reprinted in Commentat. arithm. 1, 1849, pp. 538-548 [E445b]
• A partial translation of what he considers to be the interesting parts of the paper was done by Erik Temple Bell, and appears on pp. 91-94 of Smith's Source Book in Mathematics (1929, McGraw-Hill).

• Original Publication: E445
• English Translation (Jordan Bell): E445
  
  
• The Euler Archive attempts to monitor current scholarship for articles and books that may be of interest to Euler Scholars. Selected references we have found that discuss or cite E445 include:
  • Pieper H., “On Euler's contributions to the 4-squares theorem.” Historia Mathematica, 20 (1), pp. 12-18 (Feb 1993).