One day, one decomposition
A179188: Numbers n such that phi(n) = phi(n+6), with Euler's totient function phi=A000010

3D graph, threejs - webGL https://decompwlj.com/3Dgraph/A179188.html
2D graph, first 500 terms https://decompwlj.com/2Dgraph500terms/A179188.html

One day, one decomposition
A179016: The infinite trunk of binary beanstalk: The only infinite sequence such that a(n-1) = a(n) - number of 1's in binary representation of a(n)

3D graph, threejs - webGL https://decompwlj.com/3Dgraph/A179016.html
2D graph, first 500 terms https://decompwlj.com/2Dgraph500terms/A179016.html

One day, one decomposition
A178403: Numbers containing the rounded up arithmetic mean of their digits at least once, cf. A004427

3D graph, threejs - webGL https://decompwlj.com/3Dgraph/A178403.html
2D graph, first 500 terms https://decompwlj.com/2Dgraph500terms/A178403.html

One day, one decomposition
A178361: Numbers with rounded up arithmetic mean of digits = 1

3D graph, threejs - webGL https://decompwlj.com/3Dgraph/A178361.html
2D graph, first 500 terms https://decompwlj.com/2Dgraph500terms/A178361.html

One day, one decomposition
A177729: Positive integers which do not appear in a Collatz sequence starting from a smaller positive integer

3D graph, threejs - webGL https://decompwlj.com/3Dgraph/A177729.html
2D graph, first 500 terms https://decompwlj.com/2Dgraph500terms/A177729.html

A delightful tribute: "Numbers" by Mary Collins. An excerpt:

"Even subtraction is never loss,
just addition somewhere else:
five sparrows take away two,
the two in someone else’s
garden now."

https://poetrying.wordpress.com/2014/11/12/numbers-mary-cornish/

someone who's good at #numbers please help. say i have a table with 16 items on it, and i roll a d20 to determine which item to select. if i choose to count the larger numbers over (treating a 17 as 1, 18 as 2, and so on), what are the odds of ending up with one of the first four items as opposed to one of the rest? i cannot figure out how to make it make sense.

any medical nerds want to peek inside my unhappy fucking blood results, here you go:

"ALT:ALP RATIO: 1.0 and
Normal range: 0.0 to 1.0 .

Serum ALT level: 79 iu/L and
Normal range: 7 to 40 .

Total white cell count: 19.9 10 * 9/L and
Normal range: 4.0 to 11.0 .

Mean corpuscular volume (MCV): 100.7 fL and
Normal range: 76.0 to 100.0 .

Mean corpusc. haemoglobin(MCH): 32.7 pg and
Normal range: 27.0 to 32.0 .

Neutrophil count: 16.1 10 * 9/L and
Normal range: 2.0 to 7.5 .

Monocyte count: 1.4 10 * 9/L and
Normal range: 0.2 to 0.8 ."

the rest were all within bounds.

Cool, all die mathematischen Posts zum Jahr 2025, die nun überall zu sehen sind!

2025 = (20+25)² = 45² = 9² x 5² =

40²+ 20²+5² =

1³+2³+3³+4³+5³+6³+7³+8³+9³ =

(1+2+3+4+5+6+7+8+9)² =

(123 - 4! x 5) x 678- 9

Ich wünsche allen ein nicht nur in Zahlen schönes Jahr 2025!

Dan's Question of the Day

Good morning! My question today is about JavaScript numbers & arrays!
Easy, right?

What will happen when you run this code?

#js #javascript #typescript
#advanced #numbers #quiz

#Canadian #DragQueen & #Math Communicator Kyne Santos talks with #ScienceQuickly & #ScientificAmerican:

Is Math Part of #Nature or an Invention of the #Mind?

…"One school of thought is called #intuitionism, which is the idea that math is all in our heads, and any #mathematical #truth is only true insofar as we believe that it’s true"…

https://en.wikipedia.org/wiki/Kyne_(drag_queen)
https://www.scientificamerican.com/podcast/episode/breaking-down-what-math-really-is-with-drag-queen-kyne-santos/ 27 Sep 2024

A repost of a question I asked on Twitter in 2020:

I want as many different conventions for writing numbers as you can give me. I'm interested in contexts where there are different rules for how numbers are written, e.g. scientific notation, percentages, currencies.
I'm also interested in 'optional' things like grouping digits