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 A078159 a(n) = A055086(2^n). 3
 2, 3, 4, 7, 10, 15, 21, 31, 44, 63, 89, 127, 180, 255, 361, 511, 723, 1023, 1447, 2047, 2895, 4095, 5791, 8191, 11584, 16383, 23169, 32767, 46339, 65535, 92680, 131071, 185362, 262143, 370726, 524287, 741454, 1048575, 1482909, 2097151, 2965819, 4194303, 5931640, 8388607 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(2n-2)=2^n-1 and a(n)=2a(n-2)+1 generally. LINKS Table of n, a(n) for n=1..44. MATHEMATICA Table[ Length[ Union[ Table[ Floor[2^w/j], {j, 1, 2^w}]]], {w, 1, 25}] PROG (PARI) a(n) = ceil(2*sqrt(2^n+1)) - 2; \\ Michel Marcus, Sep 02 2019 CROSSREFS Cf. A055086, A078160, A078161 & A078162. Sequence in context: A145467 A325341 A039841 * A129490 A018132 A329758 Adjacent sequences: A078156 A078157 A078158 * A078160 A078161 A078162 KEYWORD nonn AUTHOR Labos Elemer, Nov 27 2002 EXTENSIONS Extended by Robert G. Wilson v, Dec 02 2002 More terms from Michel Marcus, Sep 02 2019 STATUS approved

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Last modified May 20 14:08 EDT 2024. Contains 372717 sequences. (Running on oeis4.)