Arithmetic sequence calculator and problems solver
This online calculator solves common arithmetic sequences problems.
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This online calculator can solve arithmetic sequences problems. Currently, it can help you with the two common types of problems:

Find the nth term of an arithmetic sequence given mth term and the common difference. Example problem: An arithmetic sequence has a common difference equal to 10 and its 5th term is equal to 52. Find its 15th term.
 Find the nth term of an arithmetic sequence given ith term and jth term. Example problem: An arithmetic sequence has a its 5th term equal to 12 and its 15th term equal to 52. Find its 20th term.
Some theory and description of the solutions can be found below the calculator.
Arithmetic sequence
To recall, an arithmetic sequence, or arithmetic progression (AP) is a sequence of numbers such that the difference, named common difference, of two successive members of the sequence is a constant.
Thus, the formula for the nth term is
and in general
,
where d is the common difference.
You can solve first type of problems, listed above, by using general formula directly, or by calculating the first term a1, using the formula
and then using the formula for the nth term.
For the second type of problems, first you need to find common difference using the following formula derived from the general formula
After that, it becomes the first type of problem.
For the convinience, the calculator above also calculates the first term and general formula for the nth term of an arithmetic sequence.
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