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 A109405 #16 Jan 22 2023 11:44:09
%S A109405 36,736,8736,48736,948736,2948736,32948736,432948736,3432948736,
%T A109405 53432948736,353432948736,5353432948736,75353432948736,75353432948736,
%U A109405 5075353432948736,15075353432948736,615075353432948736
%N A109405 a(2) = 36; for n >= 3, a(n) = 2^a(n-1) mod 10^n.
%C A109405 Decimal digits read backwards form A133612.
%C A109405 Related to but different from A064541 and A121319.
%H A109405 Harvey P. Dale, <a href="/A109405/b109405.txt">Table of n, a(n) for n = 2..1000</a>
%t A109405 a = 36; For[n = 3, n < 25, n++, a = PowerMod[2, a, 10^n]; Print[a]] (* _Stefan Steinerberger_, May 25 2007 *)
%t A109405 nxt[{n_,a_}]:={n+1,PowerMod[2,a,10^(n+1)]}; NestList[nxt,{2,36},20][[All,2]] (* _Harvey P. Dale_, Jan 22 2023 *)
%Y A109405 Same as A113627 except for the initial term (14). - _Max Alekseyev_, May 11 2007
%K A109405 nonn
%O A109405 2,1
%A A109405 _N. J. A. Sloane_, following email from _Max Alekseyev_, May 06 2007
%E A109405 More terms from _Stefan Steinerberger_, May 25 2007