{"image_url":"https://images-fe.ssl-images-amazon.com/images/I/41J3TjWsxqL._SL160_.jpg","height":"190","width":"100%","author_url":"https://blog.hatena.ne.jp/koki-h/","author_name":"koki-h","title":"\u03c0\uff08\u5186\u5468\u7387\uff09\u306e\u8fd1\u4f3c\u3092\u8a08\u7b97\u3057\u3066\u307f\u305f","blog_url":"https://koki-h.hatenadiary.org/","categories":["Ruby"],"type":"rich","description":"\u30b5\u30a4\u30e2\u30f3\u30fb\u30b7\u30f3\u306e\u30d5\u30a7\u30eb\u30de\u30fc\u306e\u6700\u7d42\u5b9a\u7406\u3092\u8aad\u3093\u3067\u305f\u3089\u03c0\uff08\u5186\u5468\u7387\uff09\u306e\u8fd1\u4f3c\u3092\u6c42\u3081\u308b\u8a71\u304c\u306a\u3093\u304b\u306e\u4f8b\u3068\u3057\u3066\u51fa\u3066\u3044\u305f\u3002 \u03c0 = 4 * (1/1 - 1/3 + 1/5 - 1/7 + 1/9 - 1/11 + 1/13 - 1/15 \u2026) \u3068\u8a00\u3046\u8a08\u7b97\u3092\u305a\u3063\u3068\u3084\u3063\u3066\u3044\u304f\u3068\u8fd1\u4f3c\u5024\u3092\u6c42\u3081\u3089\u308c\u308b\u305d\u3046\u3060\u3002 \uff1c\u8ffd\u8a18 2008/12/15\uff1e \u3069\u3046\u3057\u3066\u3053\u306e\u8a08\u7b97\u3067\u6c42\u3081\u3089\u308c\u308b\u306e\u304b\u3068\u3044\u3046\u7406\u5c48\u306f\u4f55\u304b\u3068\u3044\u3046\u3068\u4ee5\u4e0b\u306e\u52d5\u753b\u3067\u8aac\u660e\u3057\u3066\u3044\u308b\u5185\u5bb9\u306e\u3088\u3046\u3060\u3002 http://jp.youtube.com/watch?v=c7rUr77gtO4(via http://d.hatena.ne.jp/satoshis/20081215/p1)\u4e0a\u306e\u5f0f\u3092\u2026","published":"2008-10-17 22:02:12","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fkoki-h.hatenadiary.org%2Fentry%2F20081017%2F1224248532\" title=\"\u03c0\uff08\u5186\u5468\u7387\uff09\u306e\u8fd1\u4f3c\u3092\u8a08\u7b97\u3057\u3066\u307f\u305f - \u6a4b\u672c\u5e78\u6a39\u306e\u7121\u611b\u60f3\u306a\u65e5\u8a18\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","version":"1.0","provider_name":"Hatena Blog","url":"https://koki-h.hatenadiary.org/entry/20081017/1224248532","blog_title":"\u6a4b\u672c\u5e78\u6a39\u306e\u7121\u611b\u60f3\u306a\u65e5\u8a18","provider_url":"https://hatena.blog"}