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 A243614 Irregular triangular array of numerators of the positive rational numbers ordered as in Comments. 5
 1, 2, 3, 1, 4, 3, 2, 5, 5, 5, 3, 1, 6, 7, 8, 7, 4, 4, 3, 2, 7, 9, 11, 11, 7, 9, 8, 7, 5, 5, 5, 3, 1, 8, 11, 14, 15, 10, 14, 13, 12, 11, 12, 13, 10, 5, 6, 7, 8, 7, 4, 4, 3, 2, 9, 13, 17, 19, 13, 19, 18, 17, 17, 19, 21, 17, 9, 13, 16, 19, 18, 11, 13, 11, 9, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Let F = A000045 (the Fibonacci numbers).  Decree that (row 1) = (1) and (row 2) = (2).  Thereafter, row n consists of F(n) numbers in decreasing order, specifically, F(n-1) numbers x+1 from x in row n-1, together with F(n-2) numbers x/(x+1) from x in row n-2.  The resulting array is also obtained by deleting from the array at A243611 all except the positive numbers and then reversing the rows. LINKS Clark Kimberling, Table of n, a(n) for n = 1..1500 EXAMPLE First 6 rows of the array of all positive rationals: 1/1 2/1 3/1 .. 1/2 4/1 .. 3/2 .. 2/3 5/1 .. 5/2 .. 5/3 .. 3/4 .. 1/3 6/1 .. 7/2 .. 8/3 .. 7/4 .. 4/3 .. 4/5 .. 3/5 .. 2/5 The numerators, by rows:  1,2,3,1,4,3,2,5,5,5,3,1,6,7,8,7,4,4,3,2... MATHEMATICA z = 12; g[1] = {0}; f1[x_] := x + 1; f2[x_] := -1/(x + 1); h[1] = g[1]; b[n_] := b[n] = DeleteDuplicates[Union[f1[g[n - 1]], f2[g[n - 1]]]]; h[n_] := h[n] = Union[h[n - 1], g[n - 1]]; g[n_] := g[n] = Complement [b[n], Intersection[b[n], h[n]]] u = Table[g[n], {n, 1, z}] v = Table[Reverse[Drop[g[n], Fibonacci[n - 1]]], {n, 2, z}] Delete[Flatten[Denominator[u]], 6]  (* A243611 *) Delete[Flatten[Numerator[u]], 6]    (* A243612 *) Delete[Flatten[Denominator[v]], 2]  (* A243613 *) Delete[Flatten[Numerator[v]], 2]    (* A243614 *) CROSSREFS Cf. A243611, A243612, A243613, A000045. Sequence in context: A006021 A002186 A125936 * A200942 A286234 A161621 Adjacent sequences:  A243611 A243612 A243613 * A243615 A243616 A243617 KEYWORD nonn,easy,tabf,frac AUTHOR Clark Kimberling, Jun 08 2014 STATUS approved

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Last modified June 21 17:44 EDT 2021. Contains 345365 sequences. (Running on oeis4.)