antony-mathematics: notebook

antony-mathematics: notebook https://antonyp.com/notebook Short notes on mathematics https://antonyp.com/assets/card.png antony-mathematics: notebook https://antonyp.com/notebook 76 144 quarto-1.11.9 Mon, 02 Nov 2026 00:00:00 GMT Odd numbers make squares Antony https://antonyp.com/notes/2026-11-02-sum-of-odds

$1 + 3 + 5 + \cdots + (2n-1) = n^2$ . Picture an $n \times n$ grid of dots and peel it into L-shaped layers from one corner: the layers have $1, 3, 5, \dots$ dots. No induction required.

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