{"url":"https://jeneshicc.hatenadiary.org/entry/20090113/1231866148","title":"Problem 173","image_url":null,"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fjeneshicc.hatenadiary.org%2Fentry%2F20090113%2F1231866148\" title=\"Problem 173 - \u843d\u66f8\u304d\u3001\u6642\u3005\u843d\u5b66\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","provider_url":"https://hatena.blog","author_name":"jeneshicc","categories":["Project Euler","Haskell"],"blog_title":"\u843d\u66f8\u304d\u3001\u6642\u3005\u843d\u5b66","height":"190","published":"2009-01-13 02:02:28","width":"100%","version":"1.0","description":"http://projecteuler.net/index.php?section=problems&id=173 \u56de\u7b54\u8005\u304c\u591a\u3044\u3060\u3051\u3042\u3063\u3066\u7c21\u5358\u3002 lamina :: Integer -> Integer lamina n = (sum.map (div n)) [4,8..4*m] - div (m*(m+1)) 2 where m = floor.sqrt.fromInteger.div n $ 4 p173 = lamina $ 10^6","author_url":"https://blog.hatena.ne.jp/jeneshicc/","provider_name":"Hatena Blog","type":"rich","blog_url":"https://jeneshicc.hatenadiary.org/"}