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 A199833 #18 Jul 14 2022 09:59:07 %S A199833 4,40,140,336,660,1144,1820,2720,3876,5320,7084,9200,11700,14616, %T A199833 17980,21824,26180,31080,36556,42640,49364,56760,64860,73696,83300, %U A199833 93704,104940,117040,130036,143960,158844,174720,191620,209576,228620,248784 %N A199833 Number of -n..n arrays of 4 elements with zero sum and no two neighbors summing to zero. %H A199833 R. H. Hardin, <a href="/A199833/b199833.txt">Table of n, a(n) for n = 1..200</a> %F A199833 Empirical: a(n) = (16/3)*n^3 - (4/3)*n = 4*A000447(n). %F A199833 Empirical: G.f.: 4*x*(1+6*x+x^2) / (x-1)^4 . - _R. J. Mathar_, Aug 01 2014 %F A199833 Empirical: partial sums of A016826. - _Sean A. Irvine_, Jul 13 2022 %e A199833 Some solutions for n=3: %e A199833 0 -3 -3 0 0 0 -1 1 1 -1 0 0 -3 -2 -1 -2 %e A199833 -2 2 -1 3 1 1 0 1 -2 2 -2 1 2 1 -3 0 %e A199833 3 3 2 0 2 1 -1 -3 1 0 0 0 -1 -2 1 1 %e A199833 -1 -2 2 -3 -3 -2 2 1 0 -1 2 -1 2 3 3 1 %Y A199833 Row 2 of A199832. %Y A199833 Cf. A000447, A016826. %K A199833 nonn %O A199833 1,1 %A A199833 _R. H. Hardin_, Nov 11 2011