A258050 Position of -n in A258047 after deleting the initial 0.

3, 6, 8, 10, 12, 13, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 35, 37, 39, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124

Offset

1,1

Comments

A258047 = (0,1,2,-1,3,6,-7,5,-3,7,...). Remove the initial 0 to get (1,2,-1,3,6,-7,5,6,-3,7,...), and note that (1,2,3,4,...) occupy positions 1,2,4,7,..., (as in A258049) and that (-1,-2,-3,...) occupy positions 3,6,8,... (as in A258050).

Links

Clark Kimberling, Table of n, a(n) for n = 1..1000

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]]], {500}];
-1 + Flatten[Position[Sign[f], 1]]  (* A258049 *)
-1 + Flatten[Position[Sign[f], -1]] (* A258050 *) (* Peter J. C. Moses, May 14 2015 *)

Crossrefs

Cf. A258047, A258049 (complement).

Sequence in context: A108769 A286754 A186387 * A185547 A112234 A189467

Adjacent sequences: A258047 A258048 A258049 * A258051 A258052 A258053

Keyword

nonn,easy

Author

Clark Kimberling, Jun 05 2015

Status

approved