72 lines
5.0 KiB
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72 lines
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HTML
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<h2>Coded triangle numbers</h2><div class="info" style="cursor:help;width:200px;margin-bottom:10px;"><h3>Problem 42</h3><span style="width:300px;color:#666;">Published on Friday, 25th April 2003, 06:00 pm; Solved by 35451</span></div>
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<p>The <i>n</i><sup>th</sup> term of the sequence of triangle numbers is given by, <i>t<sub>n</sub></i> = ½<i>n</i>(<i>n</i>+1); so the first ten triangle numbers are:</p>
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<p style='text-align:center;'>1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...</p>
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<p>By converting each letter in a word to a number corresponding to its alphabetical position and adding these values we form a word value. For example, the word value for SKY is 19 + 11 + 25 = 55 = <i>t</i><sub>10</sub>. If the word value is a triangle number then we shall call the word a triangle word.</p>
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<p>Using <a href='project/words.txt'>words.txt</a> (right click and 'Save Link/Target As...'), a 16K text file containing nearly two-thousand common English words, how many are triangle words?</p>
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