{"published":"2023-10-23 12:00:00","height":"190","title":"Java\u3067\u30e1\u30eb\u30bb\u30f3\u30cc\u6570\u3092\u6c42\u3081\u308b","provider_name":"Hatena Blog","image_url":"https://cdn-ak.f.st-hatena.com/images/fotolife/n/nainaistar/20231020/20231020103036.png","url":"https://nainaistar.hatenablog.com/entry/calc-mersenne-in-java","version":"1.0","description":"Java\u3067\u30e1\u30eb\u30bb\u30f3\u30cc\u6570\uff082\u306e\u51aa-1\uff09\u3092\u6c42\u3081\u308b\u65b9\u6cd5\u3092\u8a18\u8f09\u3057\u307e\u3059\u3002 \u30e1\u30eb\u30bb\u30f3\u30cc\u6570\u306b\u3064\u3044\u3066\u306fWikipedia\u3092\u53c2\u8003\u306b\u3057\u3066\u304f\u3060\u3055\u3044\u3002 \u524d\u63d0 Java 21 \u5bfe\u5fdc 2\u306e\u51aa-1\u304c\u6574\u6570\u3068\u306a\u308b\u5024\u3092\u6c42\u3081\u308b\u305f\u3081\u306b\u6b21\u306e\u5f0f\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002 private static boolean isMersenne(int value) { return log2(value + 1) % 1 == 0; } public static double log2(int value) { return Math.log(value) / Math.log(2); } \u89e3\u8aac 2\u306e\u51aa-1 = \u30e1\u30eb\u30bb\u30f3\u30cc\u6570\u3067\u3059\u306e\u3067\u3001\u5f0f\u5909\u5f62\u3057\u30662\u306e\u51aa=\u2026","blog_url":"https://nainaistar.hatenablog.com/","width":"100%","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fnainaistar.hatenablog.com%2Fentry%2Fcalc-mersenne-in-java\" title=\"Java\u3067\u30e1\u30eb\u30bb\u30f3\u30cc\u6570\u3092\u6c42\u3081\u308b - \u304d\u308a\u4e38\u306e\u6280\u8853\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>","author_url":"https://blog.hatena.ne.jp/nainaistar/","author_name":"nainaistar","blog_title":"\u304d\u308a\u4e38\u306e\u6280\u8853\u65e5\u8a18","type":"rich","provider_url":"https://hatena.blog","categories":["Java","\u6280\u8853"]}