# Carnival of Mathematics #197

DevFeed: [Carnival of Mathematics #197](<https://devfeed.tech/articles/carnival-of-mathematics-197-40448.md>)

Original publisher: [Read original article](<https://www.jeremykun.com/2021/09/01/carnival-of-mathematics-197/>)

Published: 2021-09-01T08:00:00Z

Content type: article

Language: en

Sources: [Jeremy Kun](<https://devfeed.tech/sources/jeremy-kun.md>)

Topics: [Mathematics](<https://devfeed.tech/topics/mathematics.md>), [Graphics](<https://devfeed.tech/topics/graphics.md>), [Simulation](<https://devfeed.tech/topics/simulation.md>), [Data Science](<https://devfeed.tech/topics/data-science.md>)

Tags: [carnival](<https://devfeed.tech/tags/carnival.md>), [dataset](<https://devfeed.tech/tags/dataset.md>), [fibonacci](<https://devfeed.tech/tags/fibonacci.md>), [folding](<https://devfeed.tech/tags/folding.md>), [functional-analysis](<https://devfeed.tech/tags/functional-analysis.md>), [geometric-series](<https://devfeed.tech/tags/geometric-series.md>), [graphics](<https://devfeed.tech/tags/graphics.md>), [inner-product](<https://devfeed.tech/tags/inner-product.md>), [knot-theory](<https://devfeed.tech/tags/knot-theory.md>), [mathematics](<https://devfeed.tech/tags/mathematics.md>), [oeis](<https://devfeed.tech/tags/oeis.md>), [sequence](<https://devfeed.tech/tags/sequence.md>), [sieve](<https://devfeed.tech/tags/sieve.md>), [simulation](<https://devfeed.tech/tags/simulation.md>), [umap](<https://devfeed.tech/tags/umap.md>), [visualization](<https://devfeed.tech/tags/visualization.md>)

## AI overview

The 197th Carnival of Mathematics introduces the number 197 and highlights mathematical and technical topics including curve untangling, folding equilateral triangles without measurement, and criticism of UMAP and t-SNE dimensionality reduction.

## Source excerpt

Welcome to the 197th Carnival of Mathematics! 197 is an unseemly number, as you can tell by the Wikipedia page which currently says that it has "indiscriminate, excessive, or irrelevant examples." How deviant. It's also a Repfigit, which means if you start a fibonacci-type sequence with the digits 1, 9, 7, and then continue with $ a_n = a_{i-3} + a_{i-2} + a_{i-1}$, then 197 shows up in the sequence. Indeed: 1, 9, 7, 17, 33, 57, 107, 197, ...