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johndcook

johndcook on Hacker News

Re:Why Mathematica does not simplify Sinh[ArcCosh[x]] on Sunday March 15, 2026 @06:44AM (#47386099)
Thanks. That was a mess. Don't know what happened, but I fixed it this morning.
Re:Text case changes the size of QR codes on Friday November 07, 2025 @09:39AM (#45846868)
Fixed again. I missed one. :)

Thanks.

Re:Text case changes the size of QR codes on Friday November 07, 2025 @07:54AM (#45845858)
Thanks. Fixed.
Re:Mollweide map projection and Newton's method on Thursday September 25, 2025 @08:48AM (#45372114)
Yes. Thanks.
Re:A recipe for creating random fractals on Saturday August 23, 2025 @09:30PM (#45000511)
The original post had an error. I just updated the post with a correction.
Re:Evaluating a class of infinite sums in closed form on Sunday August 04, 2024 @12:31PM (#41154585)
I believe the SVG file has a transparent background, but the img tag has style="background-color:white". Some browsers honor the background-color setting and show a white background behind the equations, even in dark mode. Some do not, and so the equations appear as black-on-black.

It would be better if I altered the SVG image itself to set the background color, but I don't know how to do that. Suggestions are welcome.

Re:Evaluating a class of infinite sums in closed form on Sunday August 04, 2024 @12:06PM (#41154397)
Thanks. Fixed.
Re:Evaluating a class of infinite sums in closed form on Sunday August 04, 2024 @12:06PM (#41154396)
Thanks. Fixed.
Re:A formula for the n’th digit of πœ‹ and πœ‹^n on Monday January 16, 2023 @11:15AM (#34402092)
The paper begins by citing an equation that isn't explicitly in the book referenced. I wrote up some notes filling in a few missing details.

https://www.johndcook.com/blog/2023/01/16/pi-bernoulli-numbe...

Re:A formula for the n’th digit of πœ‹ and πœ‹^n on Sunday January 15, 2023 @07:41PM (#34395342)
I can't determine which formulas in Abramowitz and Stegun the author is appealing to at the top of the article. Page 809, at least in my edition, has no formulas. Maybe I'm overlooking something, but I don't see his formulas anywhere in chapter 23, the chapter on Bernoulli numbers.

Does anyone know which equation he is citing?

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