A026167 a(n) is the position of n in A026166.

1, 2, 4, 3, 7, 8, 10, 5, 13, 6, 16, 17, 19, 20, 22, 9, 25, 26, 28, 11, 31, 12, 34, 35, 37, 14, 40, 15, 43, 44, 46, 47, 49, 18, 52, 53, 55, 56, 58, 21, 61, 62, 64, 23, 67, 24, 70, 71, 73, 74, 76, 27, 79, 80, 82, 29, 85, 30, 88, 89, 91, 32, 94

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Comments

This permutation of the positive integers is the inverse of A026166. - Clark Kimberling, Oct 20 2019

Links

• Clark Kimberling, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A026166.

Programs

Mathematica

a[1] = 1; z = 3000;
Do[{L, R} = {n - #, n + #} &[Floor[(n - 1)/2]];
  If[! Head[a[L]] === Integer, a[L] = n, a[R] = n], {n, 2, z}];
a026166 = Most[Last[
   Last[Reap[NestWhile[# + 1 &, 1, Head[Sow[a[#]]] === Integer &]]]]]; (* A026166 *)
Flatten[Table[Position[a026166, n], {n, 1, 1000}]]  (* A026167 *)
(* Peter J. C. Moses, Oct 20 2019 *)