This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A165427 #15 Oct 19 2018 03:29:58
%S A165427 1,9,9,81,6561,43046721,1853020188851841,
%T A165427 3433683820292512484657849089281,
%U A165427 11790184577738583171520872861412518665678211592275841109096961
%N A165427 a(1) = 1, a(2) = 9, a(n) = product of the previous terms for n >= 3.
%H A165427 G. C. Greubel, <a href="/A165427/b165427.txt">Table of n, a(n) for n = 1..13</a>
%F A165427 a(1) = 1, a(2) = 9, a(n) = Product_{i = 1..n-1} a(i), n >= 3.
%F A165427 a(1) = 1, a(2) = 9, a(n) = A001019(2^(n-3)) = 9^(2^(n-3)), n >= 3.
%F A165427 a(1) = 1, a(2) = 9, a(3) = 9, a(n) = (a(n-1))^2, n >= 4.
%F A165427 a(n) = A011764(n-2), n > 2. - _R. J. Mathar_, Sep 20 2009
%t A165427 a[1]:= 1; a[2]:= 9; a[n_]:= Product[a[j], {j,1,n-1}]; Table[a[n],{n,1, 12}] (* _G. C. Greubel_, Oct 19 2018 *)
%o A165427 (PARI) {a(n) = if(n==1, 1, if(n==2, 9, prod(j=1,n-1, a(j))))};
%o A165427 for(n=1,10, print1(a(n), ", ")) \\ _G. C. Greubel_, Oct 19 2018
%K A165427 nonn,easy
%O A165427 1,2
%A A165427 _Jaroslav Krizek_, Sep 17 2009