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 A087705 First integer > n reached under iteration of map x -> (5/3)*floor(x) when started at n, or -1 if no such integer is ever reached. 5
 5, 5, 10, 35, 10, 30, 35, 15, 905, 30, 20, 35, 105, 25, 905, 210, 30, 85, 55, 35, 60, 105, 40, 2410, 905, 45, 210, 80, 50, 85, 405, 55, 155, 160, 60, 280, 105, 65, 110, 2410, 70, 905, 335, 75, 210, 130, 80, 135, 230, 85, 660, 405, 90, 1160, 155, 95, 160, 2085, 100 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 COMMENTS It is conjectured that an integer is always reached. LINKS J. C. Lagarias and N. J. A. Sloane, Approximate squaring (pdf, ps), Experimental Math., 13 (2004), 113-128. MAPLE f2 := proc(x, y) x*floor(y); end; r := 5/3; h := proc(x) local n, y; global r; y := f2(r, x); for n from 1 to 20 do if whattype(y) = 'integer' then RETURN([x, n, y]); else y := f2(r, y); fi; od: RETURN(['NULL', 'NULL', 'NULL']); end; [seq(h(n)[3], n=2..60)]; CROSSREFS Cf. A087705, A087706. Sequence in context: A298181 A290332 A302842 * A087033 A175902 A079305 Adjacent sequences:  A087702 A087703 A087704 * A087706 A087707 A087708 KEYWORD nonn AUTHOR N. J. A. Sloane, Sep 29 2003 STATUS approved

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Last modified October 18 07:42 EDT 2019. Contains 328146 sequences. (Running on oeis4.)