§Puzzle terminology · math
Triangular number
A number of the form n(n+1)/2: 1, 3, 6, 10, 15, 21, 28, ... — the count of dots in a triangle of side n.
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What is Triangular number?
A number of the form n(n+1)/2: 1, 3, 6, 10, 15, 21, 28, ... — the count of dots in a triangle of side n.
What's related to Triangular number?
Related puzzle terms include Perfect square. See the linked entries for full definitions.