Dell laptops can you install odd number memory?

Yes, you can have any number of sticks, odd or even, inside a computer nowadays. The issues that matter are that they are the appropriate speeds and types of RAM, are of a size that the motherboard can use, and do not exceed the full capacity that the motherboard can address. For example, if a motherboard indicates that it has four RAM slots and can address a total of 32GB of DDR3-1600 RAM, then that implies that the largest stick that it can address is 8GB. Therefore, do not bother to buy 16GB or 32GB sticks to put on the board because the system will not recognize them. Further, do not buy DDR2 RAM because it is cheaper as it will not fit into the DDR3 slots. Also, if you already have RAM installed that is running at, say, 1333 MHz, unless the RAM is the same price for 1333 as it is for 1600, don't bother to get the 1600 because it will be slowed down by the slower RAM and you will have wasted the money to get the faster RAM. In the corollary, however, don't buy slower RAM if you already have faster RAM. The reason being that the slower RAM will bottleneck what you already have.

As long as you stick to these simple rules, you should not run into any problems and can add any RAM upgrades that are appropriate for the motherboard.

If you have any other questions or need help choosing the appropriate upgrade, feel free to drop me a line.