Matthew Arcus
matthewarcus.bsky.social
Matthew Arcus
@matthewarcus.bsky.social
And since 2026 = 2·1013 is a semiprime, multiplying mod 2026 by any odd number not a multiple of 1013 gives a permutation of 0-2025:
January 1, 2026 at 9:26 PM
An alternative view, showing the numbers 0-2025 (in base 45) arranged nicely in the grid:
January 1, 2026 at 9:23 PM
2026 = 45²+1 which is exactly the number of coloured boxes in this image - and there are exactly 45 of each type of box, except the empty red box on the top left,which is unique. See oeis.org/A002522 for more details.
January 1, 2026 at 9:15 PM
January 26, 2025 at 12:33 PM
Here's a picture:
January 6, 2025 at 7:28 PM
A nice variation on the traditional proof of Heron's formula. Given triangle ABC with incentre I, construct IG perpendicular to BI & complete the diagram as shown. Similar triangles show that LG = βγ/r and Euclid I.43 does the rest:
January 6, 2025 at 8:33 AM
A nice visual demonstration that 2025 = 45² = (1+2+3+4+5+6+7+8+9)² = 1³+2³+3³+4³+5³+6³+7³+8³+9³:
December 28, 2024 at 7:52 PM