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 A327887 #7 Sep 30 2019 13:10:27 %S A327887 1,-1,2,-3,4,-6,8,-4,6,-9,16,-7,19,-11,17,-14,9,-28,11,-16,13,-20,15, %T A327887 -19,18,-18,27,-24,31,-21,30,-35,38,-32,21,-46,32,-22,44,-40,34,-38, %U A327887 46,-39,36,-41,47,-43,42,-44,43,-55,50,-42,52,-45,57,-53,62,-57,59 %N A327887 Infinite sequence of signed integers where each is chosen to be as small as possible (in absolute value) subject to the condition that for every k >= 1, all the k(k+1)/2 numbers in the triangle of differences of the first k terms are distinct; in case of a tie, preference is given to the positive value. %C A327887 This sequence is a signed variant of A327460. %H A327887 Rémy Sigrist, <a href="/A327887/b327887.txt">Table of n, a(n) for n = 1..5000</a> %H A327887 Rémy Sigrist, <a href="/A327887/a327887.txt">C# program for A327887</a> %F A327887 Apparently, abs(a(n)) ~ n as n tends to infinity. %e A327887 The difference table for the first 8 terms is: %e A327887 1 -1 2 -3 4 -6 8 -4 ... %e A327887 -2 3 -5 7 -10 14 -12 ... %e A327887 5 -8 12 -17 24 -26 ... %e A327887 -13 20 -29 41 -50 ... %e A327887 33 -49 70 -91 ... %e A327887 -82 119 -161 ... %e A327887 201 -280 ... %e A327887 -481 ... %e A327887 ... %o A327887 (C#) See Links section. %Y A327887 Cf. A327460. %K A327887 sign %O A327887 1,3 %A A327887 _Rémy Sigrist_, Sep 29 2019