Sequence value given index

Calculator of n-th term of a sequence (n is given).

Share calculation and page on

How to use this calculator?

Field 'Index variable'

Input a letter which represents the sequence variable. For example,
For the sequence of general term a_n= 2n+1, input 'n'.
For the sequence a_k= 8k-9, input 'k'.

Field 'Sequence'

Input the general term of the sequence that you want to evaluate for a given index.
You may input numbers, fractions, operators and functions.
- Operators : + - * / et ^ (power)
- Common functions : sqrt (= square root), log, exp, etc
- Trigonometric functions : cos, sin, tan, cot, etc.
More details

Field 'Index'

Input a whole number that is the index for which the sequence will be evaluated.

Examples

- What is the value of the sequence defined by `a_n = (4*n)/sqrt(n+1)` for n = 10 ?
Value of a₁₀

- What is an approximation of the value of the sequence defined by `U_k = cos((pi*k)/7)/(k^2+1)` for k = 5 ?
Approximation of a₅