John D. Cook
Golden iteration
Just change the key
Rolling n-sided dice to get at least n
Weak derivatives
Fourier transform of a Fourier series
Fourier transform of a flat line
Obscuring P2P nodes with Dandelion
What is a Pedersen commitment?
Solving spherical triangles
The Navigational Triangle
Line of position (LOP)
Lewis & Clark geolocation
Zero knowlege proof of compositeness
Monero subaddresses
A triangle whose interior angles sum to zero
A circle in the hyperbolic plane
Equal things that don’t look equal
Hyperbolic metric
TV tuned to a dead channel
How stealth addresses work in Monero
Weddle integration rule
Solving H_n = 100
Closest harmonic number to an integer
Closest consecutive reciprocal sum to an integer
Pythagorean triples
RSA as a pairing
Three-party Diffie-Hellman in one shot
Elliptic curve pairings in cryptography
Adding an imaginary unit to a finite field
Four generalizations of the Pythagorean theorem
Elementary symmetric polynomials and optimization
Weighting an average to minimize variance
Brownian motion and Riemann zeta
Rolling correlation
Analog of Heron’s formula on a sphere
How much is a gigawatt?
Japanese polygon theorem
Tetrahedral analog of the Pythagorean theorem
The anti-Smith chart
Impedance and Trianglular Numbers
Cross ratio
Text case changes the size of QR codes
An ancient generalization of the Pythagorean theorem
Mentally compute logs base 2
Physical Keys and Encryption Keys
Freshman’s dream
Why and how Bitcoin uses Merkle trees
How blocks are chained in a blockchain
987654321 / 123456789
Spacing the circles on the Smith chart
The Smith chart
Generating random points in Colorado
Random spherical coordinates
Distribution of correlation
Distribution of coordinates on a sphere
ODE to Fisher’s transform
Quality metrics
Turning trig identities into Fibonacci identities
Experiences with GPT-5-Codex
Ethereum’s consensus layer elliptic curve
Inverting matrices and bilinear functions
Generate random points inside a sphere
Random samples from a tetrahedron
GPT-5 for AI-assisted discovery
More on Carmichael
Differential equation on a doughnut
Zcash price doubled
RSA with multiple primes
True growth rate accounting for inflation
A quiet change to RSA
Fermat primes and tangent numbers
Memorizing a list of seed words
10x vs 10%
Time needed to factor large integers
log log x
Fitting a double exponential function to three points
Extrapolating quantum factoring
Post-quantum RSA with gargantuan keys
Conway’s pinwheel tiling
Silent Payments
An inverse problem for the quadratic equation
Inverting series that are flat at zero
Mollweide map projection and Newton’s method
1420 MHz
The AI fork in the road
Day of the week centuries from now
Learning languages with the help of algorithms
Mental math posts
Morse code beyond the solar system
Cycles in Marsaglia’s mental RNG
Monero’s seed phrase words
Area of the unit disk after a Möbius transformation
More triangle inequalities
Area of unit disk under a univalent function
Random samples from a polygon
A triangle inequality by Erdős
Randomly selecting points inside a triangle
A mental random number generator
New symbols in Unicode 17
Mandelbrot and Fat Tails
Bech32 encoding
Inferring sample size from confidence interval