If you have a Repeat with Counter setup in an ICE tree, and you want to do one thing for odd values of the loop counter, and another thing for even values, you can use the Modulo node.
Doing a modulo by 2 on the loop counter (self.CounterValue) will tell you whether the loop counter is odd (modulo by 2 = 1) or even (modulo by 2 = 0)

Here’s a [super simple] example that populates an array with different values based on whether the loop counter is odd or even.
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