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A258049 Position of n in A258047 after deleting the initial 0.

%I A258049 #7 Aug 21 2015 11:05:01
%S A258049 1,2,4,5,7,9,11,14,15,17,19,21,23,25,27,29,31,33,36,38,41,43,45,47,49,
%T A258049 51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81,83,85,87,89,91,93,95,
%U A258049 97,99,101,103,105,107,109,111,113,115,117,119,121,123,125
%N A258049 Position of n in A258047 after deleting the initial 0.
%C A258049 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).
%H A258049 Clark Kimberling, <a href="/A258049/b258049.txt">Table of n, a(n) for n = 1..1000</a>
%t A258049 {a, f} = {{1}, {0}}; Do[tmp = {#, # - Last[a]} &[Min[Complement[#, Intersection[a, #]]&[Last[a] + Complement[#, Intersection[f, #]] &[Range[2 - Last[a], -1]]]]];
%t A258049 If[! IntegerQ[tmp[[1]]], tmp = {Last[a] + #, #} &[NestWhile[# + 1 &, 1, ! (! MemberQ[f, #] && ! MemberQ[a, Last[a] - #]) &]]];
%t A258049 AppendTo[a, tmp[[1]]]; AppendTo[f, tmp[[2]]], {500}];
%t A258049 -1 + Flatten[Position[Sign[f], 1]] (* A258049 *)
%t A258049 -1 + Flatten[Position[Sign[f], -1]] (* A258050 *) (* _Peter J. C. Moses_, May 14 2015 *)
%Y A258049 Cf. A258047, A258050 (complement).
%K A258049 nonn,easy
%O A258049 1,2
%A A258049 _Clark Kimberling_, Jun 05 2015