Merge pull request Chalarangelo#468 from kriadmin/patch-2

Create geometricProgression.md

snippets/geometricProgression.md

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+### geometricProgression
+
+Initializes an array containing the numbers in the specified range where `start` and `end` are inclusive and the ratio between two terms is `step`. 
+Returns an error if `step` equals `1`.
+
+Use `Array.from()`, `Math.log()` and `Math.floor()` to create an array of the desired length, `Array.map()` to fill with the desired values in a range. 
+Omit the second argument, `start`, to use a default value of `1`.
+Omit the third argument, `step`, to use a default value of `2`.
+
+``` js
+const geometricProgression = (end, start = 1,step = 2) =>
+  Array.from({ length:Math.floor(Math.log(end/start)/Math.log(step))+1}).map((v, i) => start * (step ** (i)) )
+```
+
+```js
+geometricProgression(256); // [1, 2, 4, 8, 16, 32, 64, 128, 256]
+geometricProgression(256,3); //[3, 6, 12, 24, 48, 96, 192]
+geometricProgression(256,1,4); //[1, 4, 16, 64, 256]
+geometricProgression(256,2,1); //Gives error
+```