PageRanger, part of our utilities package that will condense the page ranges in an InDesign index.
A sample index.
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Aardvarc, 1, 2, 3, 4.
Could become:
Aardvarc 1-4.
Or
Aardvarc, 1, 2, 3, 4, 9, 21, 22, 23, 24.
Aardvarc 1-4, 9, 21-24.