Christian Lawson-Perfect @christianp@mathstodon.xyz

Hallo, new Mastodon users! Here on mathstodon.xyz we've got a couple of mathematical emoji: and . I'd love to add some more. If you can make a PNG image the same size as those, send it to me and I'll add it. Faces of famous mathematicians are an easy place to start; could we have some shapes, polyhedra, or other mathographics too?

Is this a nephroid?

The baby's stomach seems to be able to measure three hours to the second.
Is it too late to apply for the longitude prize?

Our second L-P is finally out. Early reviews describe him as "sleepy" and "cuddly".

I can't imagine what prompted this integer sequence: "Least multiple of n in which the n-th digit from left is 3."
http://oeis.org/A113558

Me on The Aperiodical: the enormous difficulty of telling the truth about escalators with statistics https://aperiodical.com/2020/09/the-enormous-difficulty-of-telling-the-truth-about-escalators-with-statistics/

Six years after the last one, I've done another Aperiodical Round Up.
Now *that's* aperiodic!
https://aperiodical.com/2020/08/aperiodical-round-up-11-more-than-you-could-ever-need-want-or-be-able-to-know/

I love it when I rediscover an integer sequence with an enormous OEIS entry: http://oeis.org/A008292

This nonsense brought to you by this nonsense: https://mathstodon.xyz/@christianp/104752021458009998

I've made a clock which runs through every permutation of a deck of cards, swapping one pair every second.
It's not very useful.
https://permutation-clock.glitch.me/

Idea: a page which shows a bijection between the first 52! unix timestamps and shuffles of a pack of cards. Once a second, it moves to the next one.

I've made a patch for just this feature at https://gist.github.com/christianp/629da435c959a6ed4853dce05dc155b4, though it's only really useful in conjunction with the rest of my mathstodon branch, which uses MathJax to render LaTeX in toot content: https://github.com/christianp/mastodon/tree/mathstodon-3.1.5

mathstodon.xyz now has a live preview and completion of LaTeX!
This has been on my to-do list for a long time. You no longer need to worry if LaTeX will display properly or not.

This is pretty dire, from a closed-access journal: these matrices are typeset using \array{cc} environments, but they just used a horizontal space instead of a column separator, so nothing is aligned.
Value added!

Not sure why so many people are reminding me that leap seconds exist.