2025/03/31 by Seiichi Azuma, Azuma, Seiichi
Mathematics · Physics and Astronomy · #11D09 #11Y50 (Primary) #11Y55 (Secondary) #Advanced Mathematical Theories #Advanced Mathematical Theories and Applications #FOS: Mathematics #Mathematics and Applications #Number Theory (math.NT)
paper · pdf · doi:10.48550/arxiv.2504.00116
openalex publication_date 2025/03/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The OEIS sequence A051221 consists of nonnegative integers of the form 10x - y2. The known values are those less than or equal to 2000 with x <= 7, and it is conjectured that no new values in this range appear for x >= 8. In this paper, we give an elementary proof that this is indeed the case by using Pell-type equations.