Extracting elements from a/an vector/array with a specific order

So assume I have a vector/array A1 of size 100 and I want to extract every third elements in A1 and form a new array that contains the 1st, 4th, 7th, 10th, 13th, and so on till the 100th element of A1. Is there a function that enables me to do that?

Answer 1

[madhan ravi]

A1(3:3:100) 
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