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 A303028 #29 Dec 13 2019 23:34:12 %S A303028 0,1,1,-1,-2,2,3,6,8,4,2,0,-3,-3,-9,-7,-15,-4,-8,3,1,8,8,14,17,18,21, %T A303028 25,34,30,37,37,52,35,39,29,37,23,20,15,14,11,3,5,-3,0,-14,-8,-25,-11, %U A303028 -29,-14,-35,-20,-45,-32,-66,-36,-66,-38,-75,-44,-81,-58,-110,-55,-90,-41,-80,-34,-63,-31,-68,-24,-47,-6,-26,3 %N A303028 a(0) = 0, a(1) = a(2) = 1; for k >= 2, a(2*k-1) = k - 1 - a(k-1) - a(k), a(2*k) = a(2*k-1) - a(k). %H A303028 Altug Alkan, <a href="/A303028/b303028.txt">Table of n, a(n) for n = 0..11000</a> %H A303028 Altug Alkan, <a href="/A303028/a303028.png">A scatterplot of first differences of a(n)</a> %H A303028 Rémy Sigrist, <a href="/A303028/a303028_1.png">Density plot of the first 11000000 terms</a> %o A303028 (PARI) a = vector(77); print1 (0", "); for (k=1, #a, print1 (a[k]=if (k<=2, 1, my (n=k\2); if (k%2==0, a[2*n-1]-a[n], n-a[n]-a[n+1]))", ")) \\ _Rémy Sigrist_, Aug 16 2018 %Y A303028 Cf. A002487, A330328 (first differences). %K A303028 sign,look,hear %O A303028 0,5 %A A303028 _Altug Alkan_, Aug 16 2018