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 A183823 #6 Jul 22 2025 09:12:54 %S A183823 3375,2377341,1661285961,1163575148283,814479338538099, %T A183823 570213177028325955,399185865558804067443,279459103250217225077847 %N A183823 1/256 the number of (n+1)X5 0..3 arrays with no 2X2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor. %C A183823 Column 4 of A183827 %e A183823 Some solutions with upper left block zero for 3X5 %e A183823 ..0..0..2..0..2....0..0..0..0..0....0..0..2..0..0....0..0..0..0..0 %e A183823 ..0..0..1..3..0....0..0..2..2..3....0..0..0..2..2....0..0..3..3..2 %e A183823 ..0..2..1..2..0....3..0..1..3..3....0..2..2..1..3....2..2..3..3..3 %K A183823 nonn %O A183823 1,1 %A A183823 _R. H. Hardin_ Jan 07 2011