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 A087704 Number of steps for iteration of map x -> (5/3)*floor(x) to reach an integer > n when started at n, or -1 if no such integer is ever reached. 2
 2, 1, 2, 4, 1, 3, 3, 1, 9, 2, 1, 2, 4, 1, 8, 5, 1, 3, 2, 1, 2, 3, 1, 9, 7, 1, 4, 2, 1, 2, 5, 1, 3, 3, 1, 4, 2, 1, 2, 8, 1, 6, 4, 1, 3, 2, 1, 2, 3, 1, 5, 4, 1, 6, 2, 1, 2, 7, 1, 3, 3, 1, 6, 2, 1, 2, 7, 1, 4, 5, 1, 3, 2, 1, 2, 3, 1, 4, 7, 1, 10, 2, 1, 2, 4, 1, 3, 3, 1, 5, 2, 1, 2, 4, 1, 8, 6, 1, 3 (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)[2], n=2..60)]; CROSSREFS Cf. A087705, A087706, A087707. Sequence in context: A110162 A199087 A306913 * A165092 A306915 A270743 Adjacent sequences:  A087701 A087702 A087703 * A087705 A087706 A087707 KEYWORD nonn AUTHOR N. J. A. Sloane, Sep 29 2003 STATUS approved

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Last modified January 16 09:13 EST 2021. Contains 340204 sequences. (Running on oeis4.)