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freeCodeCamp/curriculum/challenges/japanese/10-coding-interview-prep/project-euler/problem-261-pivotal-square-sums.md
2022-01-20 20:30:18 +01:00

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id, title, challengeType, forumTopicId, dashedName
id title challengeType forumTopicId dashedName
5900f4711000cf542c50ff84 Problem 261: Pivotal Square Sums 5 301910 problem-261-pivotal-square-sums

--description--

Let us call a positive integer k a square-pivot, if there is a pair of integers m > 0 and n ≥ k, such that the sum of the (m + 1) consecutive squares up to k equals the sum of the m consecutive squares from (n + 1) on:

{(k - m)}^2 + \ldots + k^2 = {(n + 1)}^2 + \ldots + {(n + m)}^2

Some small square-pivots are

\begin{align} & \mathbf{4}: 3^2 + \mathbf{4}^2 = 5^2 \\\\ & \mathbf{21}: {20}^2 + \mathbf{21}^2 = {29}^2 \\\\ & \mathbf{24}: {21}^2 + {22}^2 + {23}^2 + \mathbf{24}^2 = {25}^2 + {26}^2 + {27}^2 \\\\ & \mathbf{110}: {108}^2 + {109}^2 + \mathbf{110}^2 = {133}^2 + {134}^2 \\\\ \end{align}

Find the sum of all distinct square-pivots ≤ {10}^{10}.

--hints--

pivotalSquareSums() should return 238890850232021.

assert.strictEqual(pivotalSquareSums(), 238890850232021);

--seed--

--seed-contents--

function pivotalSquareSums() {

  return true;
}

pivotalSquareSums();

--solutions--

// solution required