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 A109213 #5 Jun 09 2017 13:57:33
%S A109213 1,2,2,4,8,32,184,15392,5400584,74651892640,25003708306137848,
%T A109213 6335942056759761366725617280,
%U A109213 20682199297864337408779128828731176793076928
%N A109213 Product of a(n-2) and digit reversal of a(n-1).
%C A109213 Cf. A000301 a(n) = a(n-1)*a(n-2), A004086 R(n) = digit reversal of n, A109214 a(n)=a(n-1)*R(a(n-2)).
%F A109213 a(n)=a(n-2)*R(a(n-1)).
%e A109213 a(5)=8, a(6)=32, R(32)=23, hence a(7)=8*23=184; R(184)=841, a(8)=32*841=15392, etc.
%t A109213 a[1]=1;a[2]=2;a[n_]:=a[n]=a[n-2]*FromDigits[Reverse[IntegerDigits[a[n-1]]]]; A109213=Table[a[n], {n, 13}]
%t A109213 nxt[{a_,b_}]:={b,a*IntegerReverse[b]}; NestList[nxt,{1,2},15][[All,1]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 09 2017 *)
%Y A109213 Cf. A000301, A004086, A109214.
%K A109213 base,nonn
%O A109213 1,2
%A A109213 _Zak Seidov_, Jun 22 2005