%I A086398
%S A086398 1,5,7,9,11,15,17,21,23,27,29,33,35,37,39,43,45,49,51,53,55,59,61,65,67,
%T A086398 69,71,75,77,81,83,85,87,91,93,97,99,103,105,109,111,113,115,119,121,
%U A086398 125,127,129,131,135,137,141,143,147,149,153,155,157,159,163,165,169
%N A086398 a(1)=1; a(n)=a(n-1)+2 if n is in the sequence; a(n)=a(n-1)+2 if n and 
               (n-1) are not in the sequence; a(n)=a(n-1)+4 if n is not in the sequence 
               but (n-1) is in the sequence.
%F A086398 a(n)=(1+sqrt(3))*n + O(1)
%o A086398 (PARI) x=1; y=2; z=2; t=4; an[1]=x; for(n=2,100,an[n]=if(setsearch(Set(vector(n-1,
               i,a(i))),n),a(n-1)+y,if(setsearch(Set(vector(n-1,i,a(i))),n-1),a(n-1)+t,
               a(n-1)+z)))
%Y A086398 Cf. A086377.
%Y A086398 Sequence in context: A064077 A026282 A080384 this_sequence A023380 A076190 
               A028885
%Y A086398 Adjacent sequences: A086395 A086396 A086397 this_sequence A086399 A086400 
               A086401
%K A086398 nonn
%O A086398 1,2
%A A086398 Benoit Cloitre (benoit7848c(AT)orange.fr), Sep 13 2003