Investment Studio > Expressions > Functions > Math & Trig > SERIESSUM
float seriessum(float x, float n, float m, float coefficient [, ...])
Returns the sum of a power series with terms
coefficient[1] * x^n + coefficient[2] * x^(n + m) + coefficient[3] * x^(n + 2 * m) + ...
Thus, n is the power to which the series parameter x is raised in the first term; m is the step by which n is increased in each subsequent term; and each term is multiplied by the corresponding coefficient. The number of coefficients therefore determines the number of terms.
The coefficient arguments may include arrays, in which case each array element will be treated as a separate coefficient.
Example
=seriessum(2, 0, 1.5, {3, 6, 9, 12})
equals 3 * 2^0 + 6 * 2^1.5 + 9 * 2^3 + 12 * 2^4.5 = 363.499566724111.