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 A049474 #14 Jul 06 2017 02:59:06
%S A049474 0,1,2,3,3,4,5,5,6,7,8,8,9,10,10,11,12,13,13,14,15,15,16,17,17,18,19,
%T A049474 20,20,21,22,22,23,24,25,25,26,27,27,28,29,29,30,31,32,32,33,34,34,35,
%U A049474 36,37,37,38,39,39,40,41,42,42,43,44,44,45,46,46,47
%N A049474 a(n) = ceiling(n/sqrt(2)).
%H A049474 Reinhard Zumkeller, <a href="/A049474/b049474.txt">Table of n, a(n) for n = 0..10000</a>
%t A049474 Table[Ceiling[n/Sqrt[2]], {n,0,50}] (* _G. C. Greubel_, Jul 06 2017 *)
%o A049474 (Haskell)
%o A049474 a049474 = ceiling . (/ sqrt 2) . fromIntegral
%o A049474 -- _Reinhard Zumkeller_, Jul 01 2015
%o A049474 (PARI) a(n)=if(n,sqrtint((n^2-1)\2)+1,0) \\ _Charles R Greathouse IV_, Sep 02 2015
%Y A049474 A099188(n) = 2*a(n).
%Y A049474 Cf. A049472.
%K A049474 nonn
%O A049474 0,3
%A A049474 _N. J. A. Sloane_