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 A083037 #10 Feb 07 2013 17:15:01 %S A083037 1,0,-1,0,1,0,1,2,1,0,1,0,-1,0,1,0,-1,0,-1,-2,-1,0,-1,0,1,0,-1,0,1,0, %T A083037 1,2,1,0,1,0,-1,0,1,0,1,2,1,0,1,2,1,2,3,2,1,2,1,0,1,2,1,0,1,0,-1,0,1, %U A083037 0,1,2,1,0,1,0,-1,0,1,0,-1,0,-1,-2,-1,0,-1,0,1,0,-1,0,1,0,1,2,1,0,1,0,-1,0,1,0,-1,0,-1,-2,-1,0,-1,0,1,0,-1,0,-1,-2,-1,0 %N A083037 a(n)=2*A083036(n)-n. Also -A123737(n). %H A083037 Kevin O'Bryant, Bruce Reznick and Monika Serbinowska, <a href="http://www.math.uiuc.edu/~reznick/ors.pdf">Almost alternating sums</a>, Amer. Math. Monthly, Vol. 113 (October 2006), pp. 673-688. %F A083037 O'Bryant, Reznick, & Serbinowska show that |a(n)| <= k log n + 1, with k = 1/(2 log (1 + sqrt(2))), and further a(n) > k log n + 0.78 infinitely often. - _Charles R Greathouse IV_, Feb 07 2013 %o A083037 (PARI) a(n)=-sum(i=1, n, (-1)^sqrtint(2*i^2)) \\ _Charles R Greathouse IV_, Feb 07 2013 %Y A083037 Cf. A083035, A083036, A083038, A123737. %K A083037 sign %O A083037 1,8 %A A083037 _Benoit Cloitre_, Apr 17 2003