product identification – Help me identify these dice

I have these dice. I don’t know where they came from or how I got them, and I can’t imagine what they are for. They are 20-sided dice but the numbers on the sides are bananas.

See image

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Numbers on them are:
4, 5, 7, 10, 12, 15, 16, 18, 20, 21, 24, 28, 35, 36, 42, 49, 54, 56, 64, 72

I really don’t see an overall pattern here. Opposite sides don’t add up to any consistent number. And for some reason I have two of these dice.