单词	triangular number
释义	triangular number noun : a number (such as 3, 6, 10, 15) representable by that many dots arranged in rows that form a triangle and that equals {latex}\\frac{n(n + 1)}{2}{/latex} for some positive integer value of n Word History First Known Use 1795, in the meaning defined above
随便看	grangerite grangerization grangerizations grangerize grangerized grangerizer grangerizes grangerizing grangers granges grani granici granicus granicuses granicusses granita granitas granite granite blue Granite City granite cloth granite paper Granite Peak granite-gneiss granitelike

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