A plain spreadsheet with a similar function as in Excel is available in GeoGebra. The following video shows the construction of an arithmetic sequence, use of a linear formula, and how the spreadsheet and graphics view can be connected:
To open the spreadsheets view you can either choose View --> Spreadsheet or press Ctrl + Shift + S. By highlighting two different numbers and dragging down the black cross at the bottom right corner, the arithmetic sequence will automatically be continued. A formula starts with the = sign. One can refer to different fields of the spreadsheet by the column (A, B, C, ...) and row (1, 2, 3, ...) combination, i.e. A1. A dollar sign will make the formula stick to a certain column, row or field. An example formula put in field B1 would be "= A1 + 3" and results in adding 3 to the number in field A1. By selecting numbers in two columns, right-clicking and creating a new list of points, the points will automatically appear in the graphics view window.