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 A240275 #6 Jun 02 2025 09:45:56 %S A240275 10,72,2000,49921,1363144,40760821,1277623744,41700264862, %T A240275 1401065174093,47967535279669,1662365159922179,58055815885463615, %U A240275 2037231165976598098,71699030982374305133,2527959942776102405087,89229063928826842973827 %N A240275 Number of 5Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4. %C A240275 Row 5 of A240271 %H A240275 R. H. Hardin, <a href="/A240275/b240275.txt">Table of n, a(n) for n = 1..210</a> %e A240275 Some solutions for n=4 %e A240275 ..3..2..0..2....3..2..2..0....3..0..0..0....2..0..3..3....3..2..0..3 %e A240275 ..3..2..0..0....3..1..2..0....2..3..2..2....2..0..3..3....3..1..2..3 %e A240275 ..2..3..0..2....2..3..2..0....3..2..2..2....3..0..2..2....2..1..2..2 %e A240275 ..3..2..2..0....3..0..2..2....3..1..2..0....2..3..2..2....3..0..2..0 %e A240275 ..2..1..2..2....2..1..0..0....3..2..2..0....3..1..2..0....2..3..2..2 %K A240275 nonn %O A240275 1,1 %A A240275 _R. H. Hardin_, Apr 03 2014