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  "body": "\n## Statement\n\nThe series $\\sum_{n=1}^{\\infty} \\frac{1}{n^2}$ converges, and\n$$\\sum_{n=1}^{\\infty} \\frac{1}{n^2} = 1 + \\frac{1}{4} + \\frac{1}{9} + \\cdots = \\frac{\\pi^2}{6}.$$\n\n## Remarks\n\nThe convergence follows from the [[p-series test|0ZNSSK8ZK1]] with $p = 2$. The value is the hard part.\nThe value $\\pi^2/6 \\approx 1.6449$ is $\\zeta(2)$, where $\\zeta$ is the Riemann zeta function.\nMathlib states it as `hasSum_zeta_two`.\n\n## History\n\nPietro Mengoli posed the problem in 1650.\nLeonhard Euler solved it in 1734. The problem is named after Basel, the home town of Euler.\n\n## Explanations\n\n### L1 human\n\nThe sum of the reciprocals of the squares $1, 4, 9, 16, \\dots$ is a finite number.\nSurprisingly, this number involves $\\pi$, which comes from circles.\n",
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