{"url":"https://fetburner.hatenablog.com/entry/2018/03/14/010337","blog_url":"https://fetburner.hatenablog.com/","categories":["Haskell"],"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Ffetburner.hatenablog.com%2Fentry%2F2018%2F03%2F14%2F010337\" title=\"\u30e9\u30de\u30cc\u30b8\u30e3\u30f3\u306e\u516c\u5f0f\u3067\u5186\u5468\u7387\u3092\u8a08\u7b97\u3059\u308b - fetburner.core\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","title":"\u30e9\u30de\u30cc\u30b8\u30e3\u30f3\u306e\u516c\u5f0f\u3067\u5186\u5468\u7387\u3092\u8a08\u7b97\u3059\u308b","provider_name":"Hatena Blog","width":"100%","type":"rich","author_url":"https://blog.hatena.ne.jp/fetburner/","author_name":"fetburner","height":"190","version":"1.0","provider_url":"https://hatena.blog","blog_title":"fetburner.core","published":"2018-03-14 01:03:37","description":"\u8981\u65e8 \u30e9\u30de\u30cc\u30b8\u30e3\u30f3\u306e\u516c\u5f0f$$ \\frac{4}{\\pi}=\\sum_{n=0}^{\\infty} \\frac{(-1)^n (4n)! (1123+21460n)}{882^{2n+1}(4^n n!)^4} $$\u3092\u7528\u3044\u3066\uff0c\u5186\u5468\u7387\u3092\u8a08\u7b97\u3059\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u3092Haskell\u3067\u66f8\u304d\u307e\u3057\u305f\uff0e \u30e1\u30e2\u30ea8GB\u306ePC\u3067\u52d5\u4f5c\u3055\u305b\u305f\u3068\u3053\u308d\uff0c2000\u4e07\u6841\u7a0b\u5ea6\u307e\u3067\u5b9f\u7528\u7684\u306a\u901f\u5ea6\u3067\u8a08\u7b97\u3067\u304d\u307e\u3057\u305f\uff0e","image_url":"http://chart.apis.google.com/chart?cht=tx&chl=%7B%5Cdisplaystyle%0A%5Cfrac%7B4%7D%7B%5Cpi%7D%3D%5Csum_%7Bn%3D0%7D%5E%7B%5Cinfty%7D%20%5Cfrac%7B%28-1%29%5En%20%284n%29%21%20%281103%2B21460n%29%7D%7B882%5E%7B2n%2B1%7D%284%5En%20n%21%29%5E4%7D%0A%7D"}