%I #4 Mar 30 2012 17:34:49
%S 3,1037,619697,218688017,32617225577
%N a(n) = smallest k satisfying the equation phi(k) = phi(k-1) + phi(k-2) and having just n prime factors.
%e a(1) = 3 which is prime and is the first term in A065557, a(2) = 1037 = 17*61 which is the first term in A065572, a(3) = 619697=13*73*653
%t a = Table[0, {4}]; x = y = 1; Do[ z = EulerPhi[n]; If[z == x + y, If[l = Length[ FactorInteger[ n]]; a[[l]] == 0, a[[l]] = n; Print[n]]]; x = y; y = z, {n, 3, 10^7 } ]; a
%Y Cf. A065557 and A065572.
%K hard,nonn
%O 1,1
%A _Robert G. Wilson v_, Dec 01 2001
%E a(5) from _Donovan Johnson_, Feb 05 2010