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 A183891 #7 Jul 22 2025 09:17:20 %S A183891 1,241,81751,2466535,34099017,356237575,3382161175,31040377215, %T A183891 281338882705,2538405887395,22865861038983,205856624277475, %U A183891 1852911128126185,16676836226840751,150093537945401959 %N A183891 Number of arrangements of n+3 numbers in 0..8 with each number being the sum mod 9 of three others. %C A183891 Column 8 of A183892 %H A183891 R. H. Hardin, <a href="/A183891/b183891.txt">Table of n, a(n) for n = 1..22</a> %e A183891 Some solutions for n=2 %e A183891 ..0....3....3....0....8....6....0....3....1....6....3....6....6....3....6....0 %e A183891 ..3....6....3....3....6....8....6....6....3....0....6....3....2....1....6....3 %e A183891 ..6....0....3....3....2....2....6....0....7....6....3....3....8....4....3....6 %e A183891 ..6....6....0....6....6....6....3....6....3....3....0....3....6....7....0....6 %e A183891 ..6....6....6....3....5....5....0....0....4....0....0....0....5....3....0....0 %K A183891 nonn %O A183891 1,2 %A A183891 _R. H. Hardin_ Jan 07 2011