Tim Hosgood @thosgood@mathstodon.xyz

De Rham cohomology of algebraic varieties : for affine varieties, this is theorem 1 below, and it implies a theorem for general algebraic schemes.
http://www.numdam.org/article/PMIHES_1966__29__95_0.pdf

seed phrase: Marten Kudu Gnat Pony Wasp (HQ: http://aka-san.halcy.de/quasi/3036078180.gif )

mathematicians ran out of numbers in the 1700s. since then they've been attempting to pass letters and symbols off as numbers, with varying success

I've been thinking about the fact that an n×n square grid has as many cells as a triangular lattice with n triangles on each side.
Is there a nice continuous bijection between them? When n is odd, you can at least keep one line of symmetry throughout.

3D Hilbert curve stained glass triptych done!

This is the (co)end, my only (co)friend
Article by Loregian, Fosco
In collection: Attention-grabbing titles
The present note is a recollection of the most striking and useful applications of co/end calculus. We put a considerable effort in making arguments and constructions rather explicit: after having given a series of preliminary definitions, we...
URL: http://arxiv.org/abs/1501.02503
PDF: http://arxiv.org/pdf/1501.02503v2
Entry: http://read.somethingorotherwhatever.com/entry/Loregian2015

Puzzle of the day: find a number that is a perfect square with exactly 300 times the digit 1 and where all other digits are 0.

I'll answer to the toot and give a solution there.

#maths #puzzle

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