jeneshicc https://blog.hatena.ne.jp/jeneshicc/ 落書き、時々落学 https://jeneshicc.hatenadiary.org/ Project Euler Haskell http://projecteuler.net/index.php?section=problems&id=94 また、pell equation. next (x,y) = (2*x+3*y,2*y+x) tolength x | (x+2) `mod` 3 == 0 = let a = (x+2) `div` 3 in 6*a-2 | (x-2) `mod` 3 == 0 = let a = (x-2) `div` 3 in 6*a+2 p094 = takeWhile(<10^9) . map (tolength.fst).tail.iterate next $ (2,1) 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fjeneshicc.hatenadiary.org%2Fentry%2F20081118%2F1227018237" title="Problem 94 - 落書き、時々落学" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2008-11-18 23:23:57 rich https://jeneshicc.hatenadiary.org/entry/20081118/1227018237 1.0 100%