create a cFracConvergents function

cmd/pell.go

@@ -47,13 +47,12 @@ func pell(cmd *cobra.Command, args []string) {
 		period = 2 * r
 	}
 
-	hch := gaussianBrackets(a0, big.NewInt(1), cycle(repetend))
-	kch := gaussianBrackets(big.NewInt(1), big.NewInt(0), cycle(repetend))
+	ch := cFracConvergents(a0, repetend)
 
 	for i := 1; true; i = (i + 1) % period {
-		h, k := <-hch, <-kch
+		r := <-ch
 		if i == period-1 {
-			fmt.Println(h, k)
+			fmt.Println(r.Num(), r.Denom())
 		}
 	}
 }