--- id: 5900f4521000cf542c50ff64 title: 'Problem 229: Four Representations using Squares' challengeType: 5 forumTopicId: 301872 dashedName: problem-229-four-representations-using-squares --- # --description-- Consider the number 3600. It is very special, because 3600 = 482 + 362 3600 = 202 + 2×402 3600 = 302 + 3×302 3600 = 452 + 7×152 Similarly, we find that 88201 = 992 + 2802 = 2872 + 2×542 = 2832 + 3×522 = 1972 + 7×842. In 1747, Euler proved which numbers are representable as a sum of two squares. We are interested in the numbers n which admit representations of all of the following four types: n = a12 + b12n = a22 + 2 b22n = a32 + 3 b32n = a72 + 7 b72, where the ak and bk are positive integers. There are 75373 such numbers that do not exceed 107. How many such numbers are there that do not exceed 2×109? # --hints-- `euler229()` should return 11325263. ```js assert.strictEqual(euler229(), 11325263); ``` # --seed-- ## --seed-contents-- ```js function euler229() { return true; } euler229(); ``` # --solutions-- ```js // solution required ```