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 A003603 Fractal sequence obtained from Fibonacci numbers (or Wythoff array). (Formerly M0138) 57
 1, 1, 1, 2, 1, 3, 2, 1, 4, 3, 2, 5, 1, 6, 4, 3, 7, 2, 8, 5, 1, 9, 6, 4, 10, 3, 11, 7, 2, 12, 8, 5, 13, 1, 14, 9, 6, 15, 4, 16, 10, 3, 17, 11, 7, 18, 2, 19, 12, 8, 20, 5, 21, 13, 1, 22, 14, 9, 23, 6, 24, 15, 4, 25, 16, 10, 26, 3, 27, 17, 11, 28, 7, 29, 18, 2, 30, 19, 12, 31, 8, 32, 20, 5, 33 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Length of n-th row = A000045(n); last term of n-th row = A094967(n-1); sum of n-th row = A033192(n-1). [Reinhard Zumkeller, Jan 26 2012] REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Reinhard Zumkeller, Rows n=1..20 of triangle, flattened J. H. Conway and N. J. A. Sloane, Notes on the Para-Fibonacci and related sequences C. Kimberling, Fractal sequences C. Kimberling, Numeration systems and fractal sequences, Acta Arithmetica 73 (1995) 103-117. N. J. A. Sloane, Classic Sequences FORMULA Vertical para-budding sequence: says which row of Wythoff array (starting row count at 1) contains n. If one deletes the first occurrence of 1, 2, 3, ... the sequence is unchanged. From Clark Kimberling, Oct 29 2009: (Start) The fractal sequence of the Wythoff array can be constructed without reference to the Wythoff array or Fibonacci numbers. Write initial rows: Row 1: .... 1 Row 2: .... 1 Row 3: .... 1..2 Row 4: .... 1..3..2 For n>4, to form row n+1, let k be the least positive integer not yet used; write row n, and right after the first number that is also in row n-1, place k; right after the next number that is also in row n-1, place k+1, and continue. A003603 is the concatenation of the rows. (End) EXAMPLE In the recurrence for making new rows, we get row 5 from row 4 thus: write row 4: 1,3,2, and then place 4 right after 1, and place 5 right after 2, getting 1,4,3,2,5. - Clark Kimberling, Oct 29 2009 MATHEMATICA num[n_, b_] := Last[NestWhile[{Mod[#[[1]], Last[#[[2]]]], Drop[#[[2]], -1], Append[#[[3]], Quotient[#[[1]], Last[#[[2]]]]]} &, {n, b, {}}, #[[2]] =!= {} &]]; left[n_, b_] := If[Last[num[n, b]] == 0, Dot[num[n, b], Rest[Append[Reverse[b], 0]]], n]; fractal[n_, b_] := # - Count[Last[num[Range[#], b]], 0] &@    FixedPoint[left[#, b] &, n]; Table[fractal[n, Table[Fibonacci[i], {i, 2, 12}]], {n, 30}] (* Birkas Gyorgy, Apr 13 2011 *) row[1] = row[2] = {1}; row[n_] := row[n] = Module[{ro, pos, lp, ins}, ro = row[n-1]; pos = Position[ro, Alternatives @@ Intersection[ro, row[n-2]]] // Flatten; lp = Length[pos]; ins = Range[lp] + Max[ro]; Do[ro = Insert[ro, ins[[i]], pos[[i]] + i], {i, 1, lp}]; ro]; Array[row, 9] // Flatten (* Jean-François Alcover, Jul 12 2016 *) PROG (Haskell)  -- according to Kimberling, see formula section. a003603 n k = a003603_row n !! (k-1) a003603_row n = a003603_tabl !! (n-1) a003603_tabl = [1] : [1] : wythoff [2..] [1] [1] where    wythoff is xs ys = f is xs ys [] where       f js     []     []     ws = ws : wythoff js ys ws       f js     []     [v]    ws = f js [] [] (ws ++ [v])       f (j:js) (u:us) (v:vs) ws         | u == v = f js us vs (ws ++ [v, j])         | u /= v = f (j:js) (u:us) vs (ws ++ [v]) -- Reinhard Zumkeller, Jan 26 2012 CROSSREFS Equals A019586(n) + 1. Cf. A003602, A000045, A035513, A033192, A094967, A265650. Sequence in context: A007336 A227539 A133334 * A278118 A255238 A212536 Adjacent sequences:  A003600 A003601 A003602 * A003604 A003605 A003606 KEYWORD nonn,easy,nice,eigen,tabf AUTHOR EXTENSIONS More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 29 2003 Keyword tabf added by Reinhard Zumkeller, Jan 26 2012 STATUS approved

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Last modified December 18 08:16 EST 2018. Contains 318219 sequences. (Running on oeis4.)