Trigonometric sums and summation formulas have long served as essential tools for elucidating periodic phenomena across mathematics and the physical sciences. These techniques entail the explicit ...

SIAM Journal on Numerical Analysis, Vol. 10, No. 3 (Jun., 1973), pp. 448-459 (12 pages) The problem of obtaining a best summation formula for a finite sequence of real numbers in terms of a fixed ...

A formula involving sums of the form $\sum d(n)f(n)$ and $\sum d(n)g(n)$ is derived, where $d(n)$ is the number of divisors of $n$, and $f(x), g(x)$ are Hankel ...

The meaning of Sigma in statistical analysis is a function of whether you use the upper or lower case of the letter. The uppercase use of sigma denotes a summation while the lowercase represents a ...