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 A104805 #6 Mar 27 2015 23:02:58
%S A104805 1,3,4,5,7,9,12,15,20,25,33,42,54,69,88,112,143,182,232,295,376,478,
%T A104805 609,775,986,1255,1597,2032,2585,3289,4184,5322,6770,8612,10955,13935,
%U A104805 17726,22548,28682,36484,46409,59033,75092,95519,121502,154553,196595,250073
%N A104805 "Ceiling of hypotenuses": a(n) = ceiling(sqrt(a(n-1)^2 + a(n-2)^2)), a(1)=1, a(2)=3.
%t A104805 a[n_] := a[n] = Ceiling[ Sqrt[ a[n - 1]^2 + a[n - 2]^2]]; a[1] = 1; a[2] = 3; Table[ a[n], {n, 48}] (* _Robert G. Wilson v_, Mar 28 2005 *)
%Y A104805 Cf. A104803, A104804.
%K A104805 nonn
%O A104805 1,2
%A A104805 _Zak Seidov_, Mar 26 2005
%E A104805 More terms from _Robert G. Wilson v_, Mar 28 2005