This isn't a bad or new thing
Repeatedly over the years we've had periods of time where most of the front page was filled with challenges along certain themes. Just from my memory alone, alphabet and stack-exchange-api were at one point both very popular, and to a lesser extent so were semicolon-# and I ___ the source code, you ___ the input and many others.
Unlike a lot of these, OEIS "themed" challenges are likely to be of a decent quality without even trying. So long as the OP can adequately and clearly describe how the sequence works, the challenge writes itself.
Personally, I disagree with your view that
These can make for fun challenges, but I fear that they make for an easy reputation farm and clutter the front page with identical looking challenges.
If someone writes a challenge that is clear and unique by our standards, who cares if it might be an "easy rep farm"? Rep farming is a problem if it leads to low quality, low effort posts that are detrimental to the site. These might be low effort questions, but they're certainly not low quality, and they require more effort to write than a lot of the "I X the source, you X the input" challenges.
Until these challenges start all having titles like "Golf OEIS sequence AXXXXXX", the front page is generally going to stay pretty varied. And if challenges do start getting posted with boring title, encourage some creativity in title writing.
However!
Just because these challenges are often easy to write doesn't mean they can't be improved. Having posted a number of sequence questions myself, I'm starting to get bored with the default sequence I/O rules, so in a recent challenge I switched it up a bit. There are many ways that authors can adapt their question beyond just "Here is a sequence. Golf it",\${}^*\$ and I encourage people who want to write about that "cool new sequence you just found" to think creatively about how they could make their challenge stand out more.
\${}^*\$Some examples are:
- Turn it into a fastest-code, or it's cousin criteria: "Largest term calculated within a minute"
- Switch up the task beyond the standard sequence or decision-problem rules. Calculating the next term, given the previous, can allow for some very creative solutions for the right sequence. Examining overlaps between 2 related but distinct sequences (e.g. Fibonacci and Lucas numbers) again, leads to creative approaches.
- Relate your sequence somehow with answer-chaining and cops-and-robbers, or some other non-code-golf winning criteria. This typically works best if the reason it isn't code-golf is something to do with the sequence, so isn't always applicable.
