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 A083869 a(1)=1 then a(n) is the least k>=1 such that the nested radical sqrt(a(1)^2+sqrt(a(2)^2+sqrt(a(3)^2+(....+sqrt(a(n)^2)))...) is an integer. 5
 1, 3, 55, 43631, 99515655135, 4723258824886629604131775, 589359179694820074404152604620573424809709490316113791, 13331474848620898858862175943355927686887898121894707763190978243005066121710225087713374054319814910927464555589375 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA n = sqrt(a(1)^2+sqrt(a(2)^2+sqrt(a(3)^2+(....+sqrt(a(n)^2)))...). Equals main diagonal of triangle A166994. [Paul D. Hanna, Nov 18 2009] EXAMPLE k=55 is the least integer such that sqrt(1^2+sqrt(3^2+sqrt(k^2)))=3 is an integer hence a(3)=55. CROSSREFS Cf. A166994. [Paul D. Hanna, Nov 18 2009] Sequence in context: A172950 A172962 A110058 * A290773 A119188 A111451 Adjacent sequences:  A083866 A083867 A083868 * A083870 A083871 A083872 KEYWORD nonn AUTHOR Benoit Cloitre, Jun 18 2003 STATUS approved

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Last modified September 21 02:11 EDT 2020. Contains 337266 sequences. (Running on oeis4.)