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 A283451 #12 Mar 23 2017 14:40:03
%S A283451 -1,0,-2,1,-2,2,-3,2,-4,2,-4,4,-4,4,-6,3,-7,4,-7,5,-7,5,-7,9,-5,9,-7,
%T A283451 9,-7,9,-11,6,-11,9,-12,7,-13,9,-12,10,-13,10,-14,10,-14,10,-14,18,-6,
%U A283451 19,-11,17,-9,21,-9,19,-13,17,-15,17,-15,17,-23,10,-21,17,-18,15,-24,16,-21
%N A283451 a(n) = Sum_{k=1..n} (-1)^k * A005185(k).
%H A283451 Altug Alkan, <a href="/A283451/b283451.txt">Table of n, a(n) for n = 1..10000</a>
%H A283451 Altug Alkan, <a href="/A283451/a283451.png">Alternative Scatterplot of A283451</a>
%e A283451 a(7) = -3 because -1 + 1 - 2 + 3 - 3 + 4 - 5 = -3.
%o A283451 (PARI) a=vector(1000); a[1]=a[2]=1; for(n=3, #a, a[n]=a[n-a[n-1]]+a[n-a[n-2]]); va = vector(#a, n, sum(k=1, n, (-1)^(k)*a[k]))
%Y A283451 Cf. A005185, A076268.
%K A283451 sign,look
%O A283451 1,3
%A A283451 _Altug Alkan_, Mar 07 2017