%I #5 Mar 30 2012 18:36:38
%S 1,2,2,3,2,2,3,2,2,4,2,2,2,3,2,2,3,2,2,4,2,2,2,3,2,2,3,2,2,5,2,2,2,2,
%T 3,2,2,3,2,2,3,2,2,4,2,2,2,3,2,2,3,2,2,4,2,2,2,3,2,2,3,2,2,5,2,2,2,2,
%U 3,2,2,3,2,2,3,2,2,4,2,2,2,3,2,2,3,2,2,4,2,2,2,3,2,2,3,2,2,6,2,2,2,2,2,3,2
%N Satisfies a(1)=1, a(A087160(n+1)) = a(n)+1, with a(m)=2 for all m not found in A087160, where A087160(n+2)=A087160(n+1)+a(n)+1.
%C Records form A087161: a(A087161(n))=n and satisfy recurrence: A087161(n+3) = 5*A087161(n+2) - 6*A087161(n+1) + 2*A087161(n).
%e Initialize all terms to 2. Set a(1)=1, go one term forward,
%e set a(2)=a(1)+1=2, go 2 terms forward,
%e set a(4)=a(2)+1=3, go 3 terms forward,
%e set a(7)=a(3)+1=3, go 3 terms forward,
%e set a(10)=a(4)+1=4, go 4 terms forward,
%e set a(14)=a(5)+1=3, etc.
%e The indices 1,2,4,7,10,14,... form A087160.
%Y Cf. A087160, A087161.
%K nonn
%O 1,2
%A _Paul D. Hanna_, Aug 22 2003