<div class="thumb tright"><div class="thumbinner" style="width:302px;"><a href="//commons.wikimedia.org/wiki/File:0...15_AND.svg" class="image"><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/4/48/0...15_AND.svg/300px-0...15_AND.svg.png" decoding="async" width="300" height="375" class="thumbimage" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/4/48/0...15_AND.svg/450px-0...15_AND.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/4/48/0...15_AND.svg/600px-0...15_AND.svg.png 2x" data-file-width="1127" data-file-height="1407"></a>  <div class="thumbcaption"><div class="magnify"><a href="//commons.wikimedia.org/wiki/File:0...15_AND.svg" class="internal" title="Enlarge"></a></div>The same information can be seen in this bitwise AND table. The <a href="https://en.wikipedia.org/wiki/Odious_number" class="extiw" title="w:Odious number">odious</a> fields are dark, and form the same pattern.</div></div></div>
<p>Binary <a href="https://en.wikipedia.org/wiki/Walsh_matrix" class="extiw" title="w:Walsh matrix">Walsh matrix</a> as a <a href="https://en.wikipedia.org/wiki/Matrix_multiplication" class="extiw" title="w:Matrix multiplication">product</a>
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<ul><li>White (0) and red (1): result with modulo 2 operations</li></ul><ul><li>Gray numbers: result with normal operations</li></ul>
<table><tbody><tr><td style="padding: 15px;"><a href="//commons.wikimedia.org/wiki/File:Watchduck.svg" class="image"><img alt="Watchduck.svg" src="https://upload.wikimedia.org/wikipedia/commons/thumb/d/d8/Watchduck.svg/40px-Watchduck.svg.png" decoding="async" width="40" height="46" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/d/d8/Watchduck.svg/60px-Watchduck.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/d/d8/Watchduck.svg/80px-Watchduck.svg.png 2x" data-file-width="703" data-file-height="806"></a>
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<td><a href="//commons.wikimedia.org/wiki/User:Watchduck" title="User:Watchduck">Watchduck</a><br><span style="color: gray; font-size: 80%;">You can name the author as "T. Piesk", "Tilman Piesk" or "Watchduck".</span>
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<span class="int-own-work" lang="en">Own work</span>