√(n² + 2) = [n;n,2n]

√d = n + (√d - n) mit d = n² + 2

a0 = n

    1          1      (√d + n)   (√d + n)   2n + (√d - n)       (√d - n)
-------- = -------- × -------- = -------- = ------------- = n + --------
(√d - n)   (√d - n)   (√d + n)       2            2                 2

a1 = n

    2          2      (√d + n)   2 × (√d + n)   2n + (√d - n)        (√d - n)
-------- = -------- × -------- = ------------ = ------------- = 2n + --------
(√d - n)   (√d - n)   (√d + n)         2              1                  1

a2 = 2n