Triomino -- from Wolfram MathWorld

A triomino, also known as a tromino, is a 3-polyomino. There are two free polyominoes, (the same) two one-sided polyominoes, and 6 fixed polyominoes. The free polyominoes are known as the L-triomino (or right triomino) and straight triomino, respectively. There is also a game called triomino consisting of 55 equilateral triangles, each containing three numbers from 0 to 5 at each vertex. Every combination of tiles is in the game, although those tiles with three different values are allowed

Groupoid -- from Wolfram MathWorld

SOLVED: Prove by induction that any 2 x 2n (with n > 1) chessboard

Domino and Triomino Tilings of a Chessboard

La règle du jeu du Triominos

Octomino -- from Wolfram MathWorld

Triominos

Tracing Card Paths during Perfect Shuffles - Wolfram

Polyomino -- from Wolfram MathWorld

Exploring Tetris as a Transformation Semigroup

Triominos

Domino -- from Wolfram MathWorld

Un générateur de triominos - latroussemaitresses

Fault-Free Tilings - Wolfram Demonstrations Project

Pythagorean Quadruple -- from Wolfram MathWorld