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 A183353 #8 Jul 22 2025 08:51:04 %S A183353 1,36,432,3600,24192,147456,829440,4460544,23003136,115605504, %T A183353 566231040,2727346176,12910067712 %N A183353 One quarter the number of n X n 1..4 arrays with no two neighbors of any element equal to each other. %C A183353 Diagonal of A183362 %e A183353 Some solutions for 5X5 with a(1,1)=1 %e A183353 ..1..3..2..2..4....1..2..3..1..4....1..3..3..2..2....1..1..3..4..2 %e A183353 ..2..4..1..3..4....1..4..3..2..4....1..2..4..4..3....3..2..2..4..1 %e A183353 ..3..4..1..3..2....3..4..1..2..3....3..2..1..1..3....4..4..1..3..3 %e A183353 ..1..2..2..4..1....2..2..1..4..3....4..4..3..2..4....2..3..1..2..2 %e A183353 ..4..3..3..4..1....1..3..3..4..1....1..1..3..2..1....1..3..4..4..1 %K A183353 nonn %O A183353 1,2 %A A183353 _R. H. Hardin_ Jan 04 2011