%I A139047
%S A139047 1,1,2,3,5,1,6,7,13,20,1,21,1,22,1,23,24,47,71,118,1,119,120,239,359,
%T A139047 598,1,599,600,1199,1799,2998,1,2999,3000,1,3001,3002,1,3003,3004
%N A139047 a(0)=a(1)=1. For n >= 2, if a(n-1) is coprime to n, then a(n) = a(n-1)+a(n-2). 
               Otherwise, a(n)=1.
%H A139047 Jasper Mulder, <a href="b139047.txt">Table of n, a(n) for n=0..12500</
               a>
%H A139047 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%e A139047 16 is coprime to a(15) = 23, so a(16) = a(15)+a(14) = 23+1 = 24. 20 is 
               not coprime to a(19) = 118, so a(20)=1.
%Y A139047 Sequence in context: A128047 A105870 A096534 this_sequence A121053 A132597 
               A030335
%Y A139047 Adjacent sequences: A139044 A139045 A139046 this_sequence A139048 A139049 
               A139050
%K A139047 more,nonn
%O A139047 0,3
%A A139047 Leroy Quet Jun 01 2008
%E A139047 More terms from Jasper Mulder (jasper.mulder(AT)planet.nl), Oct 12 2009