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 A250695 #6 Jul 23 2025 12:42:24 %S A250695 11736,76320,383440,1670016,6671458,25235016,92169818,329292956, %T A250695 1160994284,4064711976,14193722396,49590850136,173757950350, %U A250695 611608432408,2165540377158,7721145553812,27744881818344,100541208763000 %N A250695 Number of (4+1)X(n+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction. %C A250695 Row 4 of A250691 %H A250695 R. H. Hardin, <a href="/A250695/b250695.txt">Table of n, a(n) for n = 1..210</a> %F A250695 Empirical: a(n) = 30*a(n-1) -415*a(n-2) +3514*a(n-3) -20386*a(n-4) +85924*a(n-5) -272198*a(n-6) +661180*a(n-7) -1244717*a(n-8) +1822478*a(n-9) -2068955*a(n-10) +1802474*a(n-11) -1181760*a(n-12) +563888*a(n-13) -184752*a(n-14) +37152*a(n-15) -3456*a(n-16) %e A250695 Some solutions for n=2 %e A250695 ..2..1..0....2..2..2....2..0..0....1..0..0....3..2..1....2..2..0....1..1..0 %e A250695 ..2..2..1....0..0..0....3..1..1....1..0..0....3..2..2....2..2..2....1..1..0 %e A250695 ..1..3..3....1..1..1....2..0..0....2..2..2....3..3..3....3..3..3....3..3..3 %e A250695 ..1..3..3....0..0..0....3..2..2....0..0..0....2..2..2....2..2..2....3..3..3 %e A250695 ..1..3..3....2..2..2....1..0..0....0..0..1....2..3..3....2..2..3....3..3..3 %K A250695 nonn %O A250695 1,1 %A A250695 _R. H. Hardin_, Nov 26 2014