🌐EnglishEnglishDeutschEspañolFrançaisNederlandsPolskiPortuguêsРусскийالعربية한국어中文日本語EntityQ1386491· pop 22· linked from 385 articlesPell numberdenominator of close rational approximation to the square root of 2Wikidata factsImagePell octagons.svgSources (1)wikidata.orgvia Wikidata · CC0Available in 22 languagesEspañolFrançaisDeutsch中文日本語РусскийالعربيةArmenianBanglaCatalanGalicianConnectionsFibonacci sequenceEntityPerrin numberEntityCategoriesInteger sequencesRecurrence relationsUnsolved problems in number theory