%I
%S 1,2,3,4,5,6,9,9,9,7,8,9,10,11,12,15,15,15,13,14,15,18,18,18,18,18,18,
%T 14,16,18,25,26,24,23,22,24,20,24,24,29,28,30,29,29,27,30,28,30,27,33,
%U 33,36,32,33,27,36,36,43,36,36,38,36,36,33,32,36,39,50,48,45,39,42,37,40,42,49,44,48,48,53,48,47,42,48,44,53,48,57,52,60
%N a(n) = n for 1<=n<=6; thereafter a(n) = a(na(n3))+a(na(n6)).
%C Conjectured to be infinite.
%D D. R. Hofstadter, Curious patterns and nonpatterns in a family of metaFibonacci recursions, Lecture in Doron Zeilberger's Experimental Mathematics Seminar, Rutgers University, April 10 2014.
%H N. J. A. Sloane, <a href="/A240827/b240827.txt">Table of n, a(n) for n = 1..50000</a>
%H D. R. Hofstadter, Curious patterns and nonpatterns in a family of metaFibonacci recursions, Lecture in Doron Zeilberger's Experimental Mathematics Seminar, Rutgers University, April 10 2014; <a href="https://vimeo.com/91708646">Part 1</a>, <a href="https://vimeo.com/91710600">Part 2</a>.
%H <a href="/index/Ho#Hofstadter">Index entries for Hofstadtertype sequences</a>
%p #Q(r,s) with initial values 1,2,3,4,...
%p r:=3; s:=6;
%p a:=proc(n) option remember; global r,s;
%p if n <= s then n
%p else
%p if (a(nr) <= n) and (a(ns) <= n) then
%p a(na(nr))+a(na(ns));
%p else lprint("died with n =",n); return (1);
%p fi;
%p fi; end;
%p t2:=[seq(a(n),n=1..100)];
%o (MAGMA) I:=[1,2,3,4,5,6]; [n le 6 select I[n] else Self(nSelf(n3))+Self(nSelf(n6)): n in [1..100]]; // _Vincenzo Librandi_, Apr 16 2014
%Y Cf. A240821.
%K nonn,hear
%O 1,2
%A _N. J. A. Sloane_, Apr 15 2014
