{"version":"1.0","type":"link","title":"Nonagonal number - Newikis","description":"A nonagonal number, or an enneagonal number, is a figurate number that extends the concept of triangular and square numbers to the nonagon (a nine-sided polygon). However, unlike the triangular and square numbers, the patterns involved in the construction of nonagonal numbers are not rotationally…","provider_name":"Newikis","provider_url":"https://newikis.com","cache_age":86400}