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 A274688 #10 Jul 07 2016 02:23:49 %S A274688 -2,3,-5,7,-8,9,-11,12,-13,15,-17,19,-20,21,-23,25,-27,28,-29,31,-32, %T A274688 33,-35,36,-37,39,-41,43,-44,45,-47,48,-49,51,-52,53,-55,57,-59,60, %U A274688 -61,63,-65,67,-68,69,-71,73,-75,76,-77,79,-80,81,-83,84,-85,87,-89 %N A274688 First differences of A274687. %C A274688 This sequence and its partial sums plus one list every integer except zero. %F A274688 If n is even, a(n) = A053661(n+1); if n is odd, a(n) = -A053661(n+1) %Y A274688 Cf. A030124, A053661, A274687. %K A274688 sign %O A274688 1,1 %A A274688 _Max Barrentine_, Jul 02 2016