Bitcoin puzzle transactions?

[hushan]

I came to the term as "Bitcoin puzzle transactions" which is referring to https://www.blockchain.com/btc/tx/08389f34c98c606322740c0be6a7125d9860bb8d5cb182c02f98461e5fa6cd15, at first glance it is just a normal transaction with lots of outputs. Why is it named so? What is the puzzle in it?

[bob123]

The 'puzzle in it' is that the private keys associated to the outputs have been generated in a specific way (e.g. a specific formula).
If you look at the transaction more detailed, you'll see that the outputs are 'ordered'. Beginning with the smallest .. to the highest.

Until (including) address 17aPYR1m6pVAacXg1PTDDU7XafvK1dxvhi (0.056 BTC) the UTXO's have been claimed (puzzle solved) already.
But from address 15c9mPGLku1HuW9LRtBf4jcHVpBUt8txKz (containing 0.057 BTC) up to address 1FMcotmnqqE5M2x9DDX3VfPAPuBWArGisa (0.256 BTC) the outputs havn't been claimed yet.

If you find out how to generate the private keys (based on the earlier ones, it may be some kind of increasing difficulty / search space), you can claim those BTC. And that's the 'puzzle'.