--- id: 5900f3d51000cf542c50fee6 title: 'Problem 104: Pandigital Fibonacci ends' challengeType: 5 forumTopicId: 301728 dashedName: problem-104-pandigital-fibonacci-ends --- # --description-- The Fibonacci sequence is defined by the recurrence relation: $F_n = F_{n − 1} + F_{n − 2}$, where $F_1 = 1$ and $F_2 = 1$ It turns out that $F_{541}$, which contains 113 digits, is the first Fibonacci number for which the last nine digits are 1 - 9 pandigital (contain all the digits 1 to 9, but not necessarily in order). And $F_{2749}$, which contains 575 digits, is the first Fibonacci number for which the first nine digits are 1 - 9 pandigital. Given that $F_k$ is the first Fibonacci number for which the first nine digits AND the last nine digits are 1 - 9 pandigital, find `k`. # --hints-- `pandigitalFibonacciEnds()` should return `329468`. ```js assert.strictEqual(pandigitalFibonacciEnds(), 329468); ``` # --seed-- ## --seed-contents-- ```js function pandigitalFibonacciEnds() { return true; } pandigitalFibonacciEnds(); ``` # --solutions-- ```js // solution required ```