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 A183887 #7 Jul 22 2025 09:16:51 %S A183887 1,241,8681,63645,363749,1905097,9681073,48678653,243871365, %T A183887 1220204441,6102563585,30515709437,152584140357,762931805705, %U A183887 3814681507825,19073453656861,95367363682085,476837016657945,2384185496162945 %N A183887 Number of arrangements of n+3 numbers in 0..4 with each number being the sum mod 5 of three others. %C A183887 Column 4 of A183892 %H A183887 R. H. Hardin, <a href="/A183887/b183887.txt">Table of n, a(n) for n = 1..62</a> %e A183887 Some solutions for n=2 %e A183887 ..3....2....4....4....3....4....3....4....1....3....1....0....1....4....0....2 %e A183887 ..4....0....4....4....1....0....0....0....2....3....0....4....0....0....2....4 %e A183887 ..1....4....2....2....4....3....4....3....0....1....3....3....3....2....3....0 %e A183887 ..3....2....0....3....3....3....2....1....1....4....2....2....1....4....4....3 %e A183887 ..0....1....3....0....0....1....4....3....3....0....1....4....2....3....4....4 %K A183887 nonn %O A183887 1,2 %A A183887 _R. H. Hardin_ Jan 07 2011