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 A249471 #6 Jul 23 2025 12:01:55 %S A249471 416,6872,119932,884728,5174842,21824440,76550058,231236220,620927172, %T A249471 1512868480,3409871172,7187658694,14321688284,27179247012,49484565130, %U A249471 86796151488,147351090962,242923972126,390163791394,612170875944 %N A249471 Number of length 5+4 0..n arrays with no five consecutive terms having four times any element equal to the sum of the remaining four. %C A249471 Row 5 of A249466 %H A249471 R. H. Hardin, <a href="/A249471/b249471.txt">Table of n, a(n) for n = 1..65</a> %e A249471 Some solutions for n=3 %e A249471 ..1....2....2....0....3....0....2....1....3....1....1....3....3....2....2....3 %e A249471 ..1....3....3....3....1....0....1....1....2....1....0....2....1....1....0....2 %e A249471 ..0....2....3....0....0....3....1....0....0....2....3....1....0....2....1....3 %e A249471 ..2....1....2....2....2....0....1....3....0....1....1....3....0....3....0....1 %e A249471 ..0....0....1....1....3....2....1....2....0....2....3....0....0....1....0....0 %e A249471 ..0....3....0....3....0....0....2....1....1....1....3....2....1....2....0....1 %e A249471 ..0....0....1....0....1....0....1....0....1....0....3....2....0....3....0....3 %e A249471 ..2....0....2....3....1....0....1....1....2....2....3....0....1....2....3....1 %e A249471 ..3....2....0....2....2....0....2....2....3....3....2....0....1....0....2....1 %K A249471 nonn %O A249471 1,1 %A A249471 _R. H. Hardin_, Oct 29 2014