ABSTRACT

Although I do not know of any brute force method for solving this problem, the solution I do know requires the following clever insight. Let x equal the fraction above:

x = + +

+ +

+…

1 1

1 1

1 1

1 1 1

.

Because the fraction has the same repeating form and is infinite in extent, we can replace the entire denominator in the second term by x, and write

x x

= +1 1 .