A121047 - OEIS

%I #7 Apr 09 2014 10:15:52

%S 1,1,3,5,7,13,13,15,17,17,21,23,25,37,27,29,37,53,67,71,61,67,43,61,

%T 51,57,77,53,73,101,91,91,81,67,69,73,73,75,77,81,81,121,83,137,119,

%U 89,99,95,95,127,151,101,181,161,169,227,181,179,217,193,153,121,123,127,159

%N a(0) = a(1) = 1; for n >= 2, a(n) = the n-th integer from among those positive integers which are coprime to a(n-1)+a(n-2).

%e a(6)+a(7) = 28. 1,3,5,9,11,13,15,17,19,... is the sequence of positive integers which are coprime to 28. 17 is the 8th of these integers, so a(8) = 17.

%o (PARI) {m=64;print1(c=1,",",b=1,",");for(n=2,m,k=n;s=c+b;a=0;while(k>0,a++;if(gcd(s,a)==1,k--));print1(a,",");c=b;b=a)} - (Klaus Brockhaus, Aug 09 2006)

%K nonn

%O 0,3

%A _Leroy Quet_, Aug 08 2006

%E More terms from _Klaus Brockhaus_, Aug 09 2006