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Reference table

Geometric Sequence Table: nth term by First term (a)

Reference table of nth term for Geometric Sequence across a range of first term (a) values — exact, engine-computed figures you can read off at a glance.

By Vikram Iyer, M.Sc Mathematics · Updated Jun 2026 · 1 min read

This geometric sequence reference table shows the nth term for a range of first term (a) values, assuming a common ratio (r) of 3 and a term number (n) of 5. Every figure is computed with the same engine that powers our Geometric Sequence Calculator, so the numbers are exact.

First term (a)nth termSum of first n terms
0.540.500060.5000
181.0000121.0000
1.5121.5000181.5000
2162.0000242.0000
3243.0000363.0000
4324.0000484.0000
6486.0000726.0000
10810.00001,210.0000
141,134.00001,694.0000
201,620.00002,420.0000

How to use this table

Find the row closest to your first term (a) and read across to the nth term. For a value between two rows, the real figure sits between them — or enter your exact numbers in the Geometric Sequence Calculator for a precise answer.

Need a value that is not in the table? — the Geometric Sequence Calculator does it instantly, for free, with the formula and a worked example built in.

Continue exploring math calculators with these tools: Margin of Error Calculator, Sample Size Calculator, Confidence Interval Calculator, Coefficient of Variation Calculator, Regular Heptagon Area Calculator.

Calculators in this guide

Frequently asked questions

Each cell is computed with the standard formula using exact arithmetic — the same calculation behind our Geometric Sequence Calculator — so every figure is accurate for the stated assumptions.

Yes. The table covers common first term (a) values; for any exact figure, enter your own numbers in the Geometric Sequence Calculator.

Vikram Iyer · M.Sc Mathematics

Vikram Iyer is a mathematics educator with over fifteen years of teaching experience, specialising in making quantitative concepts clear and practical for everyday use.