Pairs with common factors: Difference between revisions
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(1 _1r2 1r2&p.@{: - +/@:(5&p:)) 1+i.1e6
196035947609</lang>
Here, <code>p.</code> calculates a polynomial (1 + (-x)/2 + (x^2)/2 in this example), <code>5&p:</code> is euler's totient function, <code>@{:</code> modifies the polynomial to only operate on the final element of a sequence, <code>+/</code> is sum and <code>+/\</code> is running sum, and <code>1+i.n</code> is the sequence of numbers 1 through n.
=={{header|Phix}}==
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