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 A113785 #8 Nov 15 2021 10:41:54
%S A113785 2,3,13,175,30651,939484151,882630469980252103,
%T A113785 779036546537560708779146801314890911,
%U A113785 606897940841168991954208317469740424253072728119076070803668647790914127
%N A113785 a(n) = a(n-1)^2 + 2*a(n-2).
%D A113785 Found in a Harpers' magazine article on Chinese civil service exam.
%t A113785 RecurrenceTable[{a[0]==2,a[1]==3,a[n]==a[n-1]^2+2a[n-2]},a,{n,10}] (* _Harvey P. Dale_, Jun 20 2017 *)
%K A113785 nonn
%O A113785 0,1
%A A113785 Bob Mckaige (bobmckz(AT)yahoo.com), Jan 20 2006
%E A113785 Edited by _Jonathan Vos Post_ and _Joshua Zucker_, Jan 24 2006