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Find the nth term and finite sum of an arithmetic sequence.
Find the nth term and finite sum of an arithmetic sequence.
first=3
difference=5
terms=20Nth term: 98
Nth-term formula: a_n = a_1 + (n - 1) × d
Substitution: 3 + (20 - 1) × 5 = 98
Sum: 1010
Sum formula: S_n = n/2 × (a_1 + a_n)
Substitution: 20/2 × (3 + 98) = 1010
Terms: 20Paste content, enter parameters or choose the files you need in “First term, difference and term count”.
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Review the result under “Sequence result”, then copy or download it after checking the output.
Result guide
The result includes the nth-term formula aₙ = a₁ + (n − 1)d and the finite-sum formula Sₙ = n(a₁ + aₙ)/2, followed by the exact values substituted for the current calculation.
It uses aₙ = a₁ + (n − 1)d for the nth term and Sₙ = n(a₁ + aₙ)/2 for the sum of the first n terms.
Yes. The first term and common difference can be signed decimal values. The term count must be a positive whole number.
A sequence is the ordered list of terms. A series is the sum of those terms. This calculator reports both the selected nth term and the finite sum through n.
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