🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPortuguêsSvenskaTiếng ViệtTürkçeРусскийالعربية中文日本語EntityQ1885380· pop 19· linked from 225 articlessquare triangular numberinteger that is both a perfect square and a triangular numberAvailable in 18 languagesEspañolFrançais中文日本語РусскийItalianoالعربيةHebrewHungarianNederlandsConnectionsprime numberEntitycontinued fractionEntityCategoriesFigurate numbersInteger sequences