Definition
Pascal's triangle
Also known as: triangle of tartaglia, tartaglia's triangle
A triangular array of numbers where each entry is the sum of the two directly above it, starting from a single 1 at the top. Each row lists the binomial coefficients, which count the head-and-tail combinations for a given number of flips: row four, for example, reads 1, 4, 6, 4, 1 — the number of ways to get zero, one, two, three or four heads in four coin flips.