%I A125727
%S A125727 1,2,3,5,8,7,15,6,12,18,19,13,32,17,4,21,25,10,16,26,42,24,20,44,14,58,
%T A125727 45,47,34,51,23,74,31,37,33,70,29,61,90,71,38,67,62,41,103,52,108,64,
%U A125727 123,87,57,40,97,83,125,96,50,30,80,110,68,54,59,49,43,92,135,91,88,39
%N A125727 a(1)=1. a(2)=2. a(n) = the smallest positive integer not occurring earlier 
               in the sequence such that a(n-2)+a(n-1) is congruent to a(n) (mod 
               n).
%H A125727 Ferenc Adorjan, <a href="b125727.txt">Table of n,a(n) for n=1,10000</
               a>
%H A125727 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%H A125727 Ferenc Adorjan, <a href="http://web.t-online.hu/fadorjan/l_quet.pdf">
               Some characteristics of Leroy Quet's permutation sequences</a>
%t A125727 f[l_List] := Block[{n = Length[l] + 1, k = Mod[ l[[ -1]] + l[[ -2]], 
               n, 1]},While[ MemberQ[l, k], k += n];Append[l, k]];Nest[f, {1, 2}, 
               70] (*Chandler*)
%o A125727 (PARI){Quet_p4(n)=/* Permutation sequence a'la Leroy Quet, A125727 */
               local(x=[1,2],k=0,w=3); for(i=3,n,if((k=(x[i-1]+x[i-2])%i)==0,k=i);
               while(bittest(w,k-1)>0,k+=i);x=concat(x,k);w+=2^(k-1));return(x)}
%Y A125727 Sequence in context: A116918 A116917 A121369 this_sequence A112337 A141804 
               A121368
%Y A125727 Adjacent sequences: A125724 A125725 A125726 this_sequence A125728 A125729 
               A125730
%K A125727 nonn
%O A125727 1,2
%A A125727 Leroy Quet Feb 02 2007
%E A125727 Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Feb 03 2007