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 A183890 #7 Jul 22 2025 09:17:13 %S A183890 16,492,57614,1172880,13388190,122033732,1030189438,8431580544, %T A183890 68127437030,547474985956,4389023189750,35147929076368, %U A183890 281325633652942,2251182017398052,18011828552749070,144104466144893120 %N A183890 Number of arrangements of n+3 numbers in 0..7 with each number being the sum mod 8 of three others. %C A183890 Column 7 of A183892 %H A183890 R. H. Hardin, <a href="/A183890/b183890.txt">Table of n, a(n) for n = 1..30</a> %e A183890 Some solutions for n=2 %e A183890 ..7....6....7....1....6....4....4....0....6....2....6....6....3....2....5....6 %e A183890 ..5....2....7....1....4....4....6....6....2....2....2....2....7....2....1....4 %e A183890 ..3....6....5....1....2....0....2....4....6....0....0....4....3....6....3....0 %e A183890 ..3....0....7....3....2....6....2....2....6....0....6....2....5....2....5....2 %e A183890 ..7....4....3....5....0....6....0....6....2....4....4....0....7....6....1....2 %K A183890 nonn %O A183890 1,1 %A A183890 _R. H. Hardin_ Jan 07 2011