A232643 Inverse permutation of the sequence of positive integers at A232642.

1, 2, 4, 3, 6, 5, 9, 8, 14, 7, 12, 11, 19, 10, 17, 16, 27, 15, 25, 24, 40, 13, 22, 21, 35, 20, 33, 32, 53, 18, 30, 29, 48, 28, 46, 45, 74, 26, 43, 42, 69, 41, 67, 66, 108, 23, 38, 37, 61, 36, 59, 58, 95, 34, 56, 55, 90, 54, 88, 87, 142, 31, 51, 50, 82, 49

Offset: 1

Author

Clark Kimberling, Nov 28 2013

Keywords

• nonn
• easy

Links

• Clark Kimberling and Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 (first 1000 terms from Clark Kimberling)

Crossrefs

Cf. A232559, A232639, A232642, A000045.

Programs

Haskell

import Data.List (elemIndex); import Data.Maybe (fromJust)
a232643 = (+ 1) . fromJust . (`elemIndex` a232642_list)
-- Reinhard Zumkeller, May 14 2015

Mathematica

z = 14; g[1] = {1}; g[2] = {2}; g[n_] := Riffle[g[n - 1] + 1, 2 g[n - 1] + 2]; 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}]]  (* A232642 *)
Table[Length[g1[n]], {n, 1, z}]  (* A000045 *)
Flatten[Table[Position[t, n], {n, 1, 200}]]  (* A232643 *)

Extensions

b-File corrected by Reinhard Zumkeller, May 14 2015