A232560 Inverse permutation of the sequence of positive integers at A232559.

1, 2, 3, 4, 6, 5, 8, 7, 11, 10, 16, 9, 14, 13, 21, 12, 19, 18, 29, 17, 27, 26, 42, 15, 24, 23, 37, 22, 35, 34, 55, 20, 32, 31, 50, 30, 48, 47, 76, 28, 45, 44, 71, 43, 69, 68, 110, 25, 40, 39, 63, 38, 61, 60, 97, 36, 58, 57, 92, 56, 90, 89, 144, 33, 53, 52

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from Clark Kimberling)

Index entries for sequences that are permutations of the natural numbers

Maple

g:= proc() local l, s; l, s:= [1], {1}:
      proc(n) option remember; local i, r; r:= l[1];
        l:= subsop(1=NULL, l);
        for i in [1+r, r+r] do if not i in s then
          l, s:=[l[], i], s union {i} fi
        od; r
      end
    end():
a:= proc() local t, a; t, a:= 0, proc() -1 end;
      proc(n) local h;
        while a(n) < 0 do
          t:= t+1; h:= g(t);
          if a(h) < 0 then a(h):= t fi
        od; a(n)
      end
    end():
seq(a(n), n=1..100);  # Alois P. Heinz, Sep 14 2021

Mathematica

z = 12; g[1] = {1}; g[2] = {2}; g[n_] := Riffle[g[n - 1] + 1, 2 g[n - 1]]; j[2] = Join[g[1], g[2]]; j[n_] := Join[j[n - 1], g[n]]; g1[n_] := DeleteDuplicates[DeleteCases[g[n], Alternatives @@ j[n - 1]]]; g1[1] = g[1]; g1[2] = g[2]; t = Flatten[Table[g1[n], {n, 1, z}]]  (* A232559 *)
Table[Length[g1[n]], {n, 1, z}] (* Fibonacci numbers *)
t1 = Flatten[Table[Position[t, n], {n, 1, 200}]]  (* A232560 *)

Crossrefs

Cf. A232559, A000045.

Sequence in context: A285041 A265734 A299759 * A183090 A232559 A094138

Adjacent sequences: A232557 A232558 A232559 * A232561 A232562 A232563

Keyword

nonn,easy

Author

Clark Kimberling, Nov 26 2013

Status

approved