I went hunting for references to the OEIS in open source code, and found some weird ones.

There are not one, but two live-coding music frameworks that use OEIS sequences as a source for “anything that can be sequenced” in music. I’m guessing that’s used for choosing pseudorandom melodies, interesting rhythyms, or how to overlap tracks in different ways.

The first project is called mercury, which is advertised as having “an extensive library of algorithms to generate or transform numbersequences that can modulate parameters.”

As far as OEIS sequences, they have A000045 (Fibonacci), A006190 (Fibonacci-like), A000032 (Lucas), A000129 (Pell), which are all Fibonacci-like.

Then there’s ziffers, which is an extension for Sonic Pi. In their ziffers/lib/enumerables.rb there are a lot more, and weirder sequences.

It has the de Bruijn sequence (A000695), Recamán’s sequence (A005132), Thue-Morse (A010060), Dress’s sequence (A001316), and many more. There are a bunch of 10-adic decimal expansions like A225410, the 10-adic integer x such that $x^3 = 7/9$, which seems…music-theory ish?

And then there’s the Inventory Sequence, A342585 (oh goodness what is going on there), which seems very much NOT music-theory ish.

My real question is: how does music that relies on these weird sequences actually sound? I can’t imagine a melody decided by the Inventory Sequence sounds very good. Every time someone does music based on the digits of pi, it’s kind of meh. But let me know if you’ve tried this.

The Kobo e-reader has a document viewing program called Plato. It has a pen tool for markup, and for whatever reason, they use A000041 (the number of partitions of n) as the options for pen size. No reasoning was given in the commit/PR that added this.

Finally, the GC wizard is a geocaching app that serves as “an offline tool to support geocachers with in-field mysteries and riddles.”

There are many hard-coded OEIS sequences and formulas in it, which leads to the amusing mental image of cache hunters standing in the wilderness, trying to decode a clue based on the look-and-say sequence, maybe using a stick to draw formulas in the dirt.