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 A202071 #7 Jul 22 2025 16:28:03 %S A202071 10,56,78,0,1014,5832,8412,0,118560,691352,1009378,0,14741482, %T A202071 86567880,127201108,0,1895190810,11176778256,16487950878,0, %U A202071 248820363000,1471592159928,2176717161564,0,33142566417012,196414950943848 %N A202071 Number of arrays of n+2 integers in -3..3 with sum zero and the sum of every adjacent pair being odd. %C A202071 Column 3 of A202076 %H A202071 R. H. Hardin, <a href="/A202071/b202071.txt">Table of n, a(n) for n = 1..210</a> %e A202071 Some solutions for n=3 %e A202071 ..2....2....0....2....0....0...-2....0....0....0....0...-2...-2....2...-2...-2 %e A202071 .-1...-1....3...-1...-1....3...-1....1...-3....1...-3....3...-3....3....3....1 %e A202071 ..2...-2....0....2...-2....0....2...-2....0....2....2....0....0...-2...-2....0 %e A202071 .-1....1...-1...-3....3...-3....1....1....3...-3....1...-1....3...-3....3....3 %e A202071 .-2....0...-2....0....0....0....0....0....0....0....0....0....2....0...-2...-2 %K A202071 nonn %O A202071 1,1 %A A202071 _R. H. Hardin_ Dec 10 2011