Pell Equation Calculator

Find solutions to Pell's equation x² - Dy² = 1 using continued fractions.

Pell Equation Parameters

About Pell Equation

Pell's equation has infinitely many solutions when D is not a perfect square.

x² - Dy² = 1

All solutions can be generated from the fundamental solution (x₁, y₁).

Recurrence Relation

xₙ₊₁ = x₁xₙ + Dy₁yₙ

yₙ₊₁ = x₁yₙ + y₁xₙ

Equation

x² - 2y² = 1

Fundamental Solution

x₁

3

y₁

2

Solutions

n = 1Valid
x = 3
y = 2
n = 2Valid
x = 17
y = 12
n = 3Valid
x = 99
y = 70
n = 4Valid
x = 577
y = 408
n = 5Valid
x = 3363
y = 2378
n = 6Valid
x = 19601
y = 13860
n = 7Valid
x = 114243
y = 80782
n = 8Valid
x = 665857
y = 470832
n = 9Valid
x = 3880899
y = 2744210
n = 10Valid
x = 22619537
y = 15994428