%I
%S 37,613566757,48611766702991209066196372490252601637
%N This is a sequence demonstrating a congruence property of second order exponential functions. Let f(n) = a^(b^n) + c where a,b,c & n belong to N, a, b & c fixed. Then f(n + k*phi(phi(f(n)) is congruent to 0 (mod(f(n)). Here k belongs to N. This is a sequence of quotients generated by f(n + k*f(n))/f(n) when a & b = 2, c= 3 and n = 1. when a & b = 2 and c =3 when n = 1.
%e a(n) = 2^2^n + 3 = 7 when n = 1. phi(phi(7)) = 2. 2^2^(1 + 2*k) + 3 = 259; 259/7 = 37.
%o (PARI) a(k)=(2^2^(1 + 2*k) + 3)/7
%K nonn,uned,bref
%O 1,1
%A _A.K. Devaraj_, Dec 08 2009
