Digital Library of Mathematical Functions
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6 Exponential, Logarithmic, Sine, and Cosine IntegralsApplications6.16 Mathematical Applications

Figure 6.16.2 (See in context.)

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Figure 6.16.2: The logarithmic integral \mathop{\mathrm{li}\/}\nolimits\!\left(x\right), together with vertical bars indicating the value of \pi(x) for x=10,20,\dots,1000.