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 A221319 #6 Jun 02 2025 08:15:43 %S A221319 1,2,7,14,30,76,188,444,1071,2638,6460,15756,38783,95778,236270, %T A221319 584394,1448972,3596146,8935547,22233108,55380945,138076092,344565415, %U A221319 860595928,2151093021,5380523278,13467284628,33729132584,84523860027,211927633632 %N A221319 Number of nonnegative integer arrays of length n summing to n without equal adjacent values modulo 6. %C A221319 Column 6 of A221321 %H A221319 R. H. Hardin, <a href="/A221319/b221319.txt">Table of n, a(n) for n = 1..210</a> %e A221319 Some solutions for n=9 %e A221319 ..0....0....2....2....0....1....1....0....1....1....1....3....0....1....0....2 %e A221319 ..1....1....0....1....2....0....2....2....0....0....0....1....1....0....2....3 %e A221319 ..0....0....4....2....1....1....0....1....1....2....3....0....0....1....0....0 %e A221319 ..2....2....0....0....0....0....1....0....0....1....1....2....2....0....1....1 %e A221319 ..3....0....1....2....1....2....2....1....1....0....0....1....1....4....0....0 %e A221319 ..0....3....0....0....0....1....1....2....0....3....1....0....0....0....4....2 %e A221319 ..1....0....1....1....2....0....0....1....1....0....2....1....4....1....0....0 %e A221319 ..0....2....0....0....0....1....2....2....3....2....1....0....0....0....2....1 %e A221319 ..2....1....1....1....3....3....0....0....2....0....0....1....1....2....0....0 %K A221319 nonn %O A221319 1,2 %A A221319 _R. H. Hardin_ Jan 10 2013