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 A104806 #2 Mar 30 2012 17:26:11 %S A104806 1,3,3,4,5,7,9,11,14,18,23,29,37,47,60,77,97,124,158,201,255,324,413, %T A104806 525,668,849,1081,1374,1748,2224,2829,3598 %N A104806 "Round of hypotenuse", see comments. %C A104806 Start with a=1, b=3; repeating procedure "c=sqrt[a^2+b^2], a=b,b=c" gives: s = 1,3, Sqrt[10], Sqrt[19], Sqrt[29], 4*Sqrt[3], Sqrt[77],5*Sqrt[5], Sqrt[202],Sqrt[327], 23, 2*Sqrt[214],Sqrt[1385], 3*Sqrt[249],... Then A104806(n)=round[s(n)]. %Y A104806 Cf. A104803, A104804, A104805. %K A104806 nonn %O A104806 1,2 %A A104806 _Zak Seidov_, Mar 26 2005