Some say the world will end in fire,
Some say in ice.
From what I’ve tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice.

The following is a simple contract for a token, "N", with a bound supply curve.
Every block a new token is made available for minting.
Every 4 years a "doubling" occurs, wherein the number of blocks passed required to mint a new token doubles.
Following this schedule, in roughly 92 years it will take 4 years to mint a single token, at which point the supply will be roughly ~21,000,000.
The supply is technically uncapped, but after 92 years no more than a handful of tokens could ever be minted before the heat death of the universe.

Alea iacta est