%I #7 Feb 14 2018 21:03:31
%S 24,19656,7625597465304,443426488243037769948249622993552407816,
%T 87189642485960958202911070585860771696964072404731750085525219437990967093722996516987306869061734867160436075772824
%N f(f(n+1))-f(f(n)), where f(m) = 3^m.
%p f:=n->3^n; g:=n->f(f(n+1))-f(f(n)); [seq(g(n),n=0..4)]; # _N. J. A. Sloane_, Feb 14 2018
%K nonn
%O 0,1
%A _N. J. A. Sloane_, Nov 12 2005