A302779 - OEIS

%I #9 Apr 27 2018 17:11:38

%S 1,1,2,3,3,4,5,5,6,6,6,7,8,7,9,10,9,11,11,12,12,12,12,13,14,15,13,13,

%T 13,13,16,17,18,16,19,20,21,22,19,22,23,23,24,24,24,24,24,25,26,27,28,

%U 29,30,31,28,32,25,28,25,25,25,25,33,34,35,36,37,38,39,33,40,36,41,42,43,39,44,43,45,46,47,48,48,49,50,51,52,52,49,53,53,53,53,53,53

%N Restricted growth sequence transform of ordered pair [Q(n-Q(n-1)), Q(n-Q(n-2))], the left & right summand of Hofstadter Q-sequence A005185.

%C Restricted growth sequence transform of A286559.

%H Antti Karttunen, <a href="/A302779/b302779.txt">Table of n, a(n) for n = 1..65537</a>

%H <a href="/index/Ho#Hofstadter">Index entries for Hofstadter-type sequences</a>

%o (PARI)

%o up_to = 65537;

%o first_n_of_A005185(n) = { my(v=vector(n)); v[1]=v[2]=1; for(k=3, n, v[k]=v[k-v[k-1]]+v[k-v[k-2]]); (v); };

%o v005185 = first_n_of_A005185(up_to);

%o A005185(n) = v005185[n];

%o Aux302779(n) = if(n<3,0,[A005185(n-A005185(n-1)), A005185(n-A005185(n-2))]);

%o rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };

%o write_to_bfile(start_offset,vec,bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }

%o write_to_bfile(1,rgs_transform(vector(up_to,n,Aux302779(n))),"b302779.txt");

%Y Cf. A005185, A286559, A302780.

%K nonn

%O 1,3

%A _Antti Karttunen_, Apr 27 2018