Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Please help me find a formula for the $a_n$ in this sequence, $$ 1,\, \frac{1}{2\sqrt 2},\, \frac{1}{3\sqrt 3},\, \ldots $$

share|improve this question

closed as off-topic by Jonas Meyer, Claude Leibovici, Casteels, user1551, Venus Jan 1 at 9:59

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." – Jonas Meyer, Claude Leibovici, Casteels, user1551, Venus
If this question can be reworded to fit the rules in the help center, please edit the question.

What do you think the next three terms are? –  Jonas Meyer Oct 2 '12 at 6:22
@JonasMeyer I have thought about it for a while now, I have no clue, tell me please. –  AD. Oct 13 '12 at 12:59

2 Answers 2

up vote 1 down vote accepted


$a_1=1=\frac{1}{1\sqrt 1}$,

$a_2=\frac{1}{2\sqrt 2}$,

$a_3=\frac{1}{3\sqrt 3}$,


$a_n=\frac{1}{n\sqrt n}$.

share|improve this answer

With this sort of problem, you really only have to come up with some sort of pattern or closed form that fits/describes what you've got so far. There could be many viable patterns--some far more obvious than others--but whatever you pick, you should be fine as long as you can justify it.

share|improve this answer