A069196 - OEIS

A069196

a(1)=1, a(2)=3; for n>1, a(n+2)=(a(n+1)+a(n))/3 if (a(n+1)+a(n)==0 (mod 3)); a(n+2)=(a(n+1)+a(n))/2 if (a(n+1)+a(n)==0 (mod 2)); and a(n+2)=a(n+1)+a(n) otherwise.

%I #6 Mar 30 2012 18:38:57

%S 1,3,2,5,7,4,11,5,8,13,7,10,17,9,13,11,8,19,9,14,23,37,20,19,13,16,29,

%T 15,22,37,59,32,91,41,44,85,43,64,107,57,82,139,221,120,341,461,401,

%U 431,416,847,421,634,1055,563,809,686,1495,727,1111,919,1015,967,991

%N a(1)=1, a(2)=3; for n>1, a(n+2)=(a(n+1)+a(n))/3 if (a(n+1)+a(n)==0 (mod 3)); a(n+2)=(a(n+1)+a(n))/2 if (a(n+1)+a(n)==0 (mod 2)); and a(n+2)=a(n+1)+a(n) otherwise.

%C A Collatz-Fibonacci mixture. Does this sequence diverge to infinity?

%Y Cf. A006369.

%K easy,nonn

%O 1,2

%A _Benoit Cloitre_, Apr 11 2002