Abstract
Let P and Q be non-zero relatively prime integers. The Lucas sequence {Un(P,Q)} is defined by U0=0, U1=1, Un=PUn-1-QUn-2 (n≥2). We show that the only sequence with U12(P,Q) a perfect square is the Fibonacci sequence {Un(1,-1)}; and we show that there are no non-degenerate sequences {Un(P,Q)} with U9(P,Q) a perfect square. The argument involves finding all rational points on several curves of genus 2.
Original language | English (US) |
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Pages (from-to) | 215-227 |
Number of pages | 13 |
Journal | Journal of Number Theory |
Volume | 107 |
Issue number | 2 |
DOIs | |
State | Published - Aug 2004 |
Keywords
- Elliptic curve
- Formal group
- Lucas sequence
ASJC Scopus subject areas
- Algebra and Number Theory