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 A113494 #5 Oct 31 2013 12:23:02 %S A113494 2,3,13,178,31853,1014645293,1029505071621669458, %T A113494 1059880692494738761409621021617069613, %U A113494 1123347082323126985848870489739619316533660939418089557571160604297983533 %N A113494 a(0) = 2, a(1) = 3; for n>1, a(n) = a(n-2)^2 + a(n-1)^2. %D A113494 Harper's Magazine, Feb 2006, Page 14. %t A113494 a[1] = 2; a[2] = 3; a[n_] := a[n - 2]^2 + a[n - 1]^2; Array[a, 9] (* _Robert G. Wilson v_ *) %Y A113494 Cf. A000283. %K A113494 nonn,easy %O A113494 0,1 %A A113494 Michael Hogan (Michael(AT)michaelhogan.com), Jan 10 2006 %E A113494 Corrected and extended by _Robert G. Wilson v_, Jan 11 2006