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 A215071 #6 Jul 22 2025 23:20:56 %S A215071 1,1,2,4,12,39,138,503,1864,6936,25868,96512,360203,1344408,5018051, %T A215071 18729944,69910398,260943079,973980990,3635421345,13569354266, %U A215071 50648137765,189046143161 %N A215071 Number of squarefree words of length n in a 5-ary alphabet, with new values 0..4 introduced in increasing order. %C A215071 Column 4 of A215075 %e A215071 Some solutions for n=6 %e A215071 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0 %e A215071 ..1....1....1....1....1....1....1....1....1....1....1....1....1....1....1....1 %e A215071 ..2....2....2....2....0....2....2....2....0....2....2....0....2....2....0....2 %e A215071 ..0....3....3....1....2....3....3....1....2....1....0....2....0....3....2....3 %e A215071 ..1....4....0....3....3....0....0....3....3....3....3....3....2....2....0....1 %e A215071 ..0....0....1....2....0....2....3....4....1....0....4....4....1....4....3....0 %K A215071 nonn %O A215071 1,3 %A A215071 _R. H. Hardin_ Aug 02 2012