Book:Murray R. Spiegel/Mathematical Handbook of Formulas and Tables/Chapter 35

Cosine Integral $\displaystyle \map \Ci x = \int_x^\infty \frac {\cos u} u \rd u$
=== Fresnel Sine Integral $\displaystyle \map {\operatorname S} x = \sqrt {\frac 2 \pi} \int_0^x \sin u^2 \rd u$ ===

=== Fresnel Cosine Integral $\displaystyle \map {\operatorname C} x = \sqrt {\frac 2 \pi} \int_0^x \cos u^2 \rd u$ ===

=== Riemann Zeta Function $\displaystyle \map \zeta x = \frac 1 {1^x} + \frac 1 {2^x} + \frac 1 {3^x} + \ldots$ ===