A256283 Smallest m such that A257905(m) = n.

1, 2, 4, 3, 7, 5, 9, 11, 14, 8, 13, 6, 17, 10, 19, 12, 21, 15, 23, 25, 27, 29, 31, 33, 38, 18, 36, 43, 41, 20, 35, 45, 47, 22, 51, 16, 53, 24, 49, 26, 40, 28, 50, 30, 57, 32, 59, 34, 55, 39, 65, 61, 63, 37, 67, 44, 71, 42, 75, 69, 77, 73, 79, 46, 81, 48, 85

Offset: 0

Author

Reinhard Zumkeller, Jun 03 2015

Keywords

• nonn

Comments

Conjectured inverse of A257905.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A257905.

Programs

Haskell

import Data.List (elemIndex); import Data.Maybe (fromJust)
a256283 = (+ 1) . fromJust . (`elemIndex` a257905_list)

Mathematica

{a, f} = {{1}, {0}}; Do[tmp = {#, # - Last[a]} &[Min[Complement[#, Intersection[a, #]]&[Last[a] + Complement[#, Intersection[f, #]] &[Range[2 - Last[a], -1]]]]];
If[! IntegerQ[tmp[[1]]], tmp = {Last[a] + #, #} &[NestWhile[# + 1 &, 1, ! (! MemberQ[f, #] && ! MemberQ[a, Last[a] - #]) &]]];
AppendTo[a, tmp[[1]]]; AppendTo[f, tmp[[2]]], {1000}]; a;
Flatten[Table[Position[a, n], {n, 1, 150}]] (* Peter J. C. Moses, May 14 2015 *)