TY - JOUR
T1 - A note on the Diophantine equations 2ln2=1+q+⋯+qα and application to odd perfect numbers
AU - Hirakawa, Yoshinosuke
N1 - Publisher Copyright:
© 2024 Royal Dutch Mathematical Society (KWG)
PY - 2024/3
Y1 - 2024/3
N2 - Let N be an odd perfect number. Then, Euler proved that there exist some integers n,α and a prime q such that N=n2qα, q∤n, and q≡α≡1mod4. In this note, we prove that the ratio [Formula presented] is neither a square nor a square times a single prime unless α=1. It is a direct consequence of a certain property of the Diophantine equation 2ln2=1+q+⋯+qα, where l denotes one or a prime, and its proof is based on the prime ideal factorization in the quadratic orders Z[1−q] and the primitive solutions of generalized Fermat equations xβ+yβ=2z2. We give also a slight generalization to odd multiply perfect numbers.
AB - Let N be an odd perfect number. Then, Euler proved that there exist some integers n,α and a prime q such that N=n2qα, q∤n, and q≡α≡1mod4. In this note, we prove that the ratio [Formula presented] is neither a square nor a square times a single prime unless α=1. It is a direct consequence of a certain property of the Diophantine equation 2ln2=1+q+⋯+qα, where l denotes one or a prime, and its proof is based on the prime ideal factorization in the quadratic orders Z[1−q] and the primitive solutions of generalized Fermat equations xβ+yβ=2z2. We give also a slight generalization to odd multiply perfect numbers.
KW - Diophantine equations
KW - Generalized Fermat equations
KW - Multiply perfect numbers
KW - Perfect numbers
UR - http://www.scopus.com/inward/record.url?scp=85183561920&partnerID=8YFLogxK
U2 - 10.1016/j.indag.2023.12.004
DO - 10.1016/j.indag.2023.12.004
M3 - Article
AN - SCOPUS:85183561920
SN - 0019-3577
VL - 35
SP - 282
EP - 287
JO - Indagationes Mathematicae
JF - Indagationes Mathematicae
IS - 2
ER -