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 A194611 #10 Jun 04 2025 00:29:57 %S A194611 36,3638,1674043,3703163910,38969955227338,1946585305112431165, %T A194611 461761593540314858209528,520265339158575595235640177020 %N A194611 Half the number of lower triangles of an (n+1) X (n+1) 0..4 array with no element equal to the average of its horizontal and vertical neighbors. %e A194611 Some solutions for 3X3 %e A194611 ..3......2......2......0......1......4......4......3......1......3......1 %e A194611 ..0.4....0.3....4.2....3.1....2.2....0.1....1.1....4.0....2.3....1.0....4.4 %e A194611 ..1.3.1..4.0.3..4.2.1..4.1.4..2.3.1..0.3.0..4.2.3..3.1.4..0.1.2..1.3.2..2.3.0 %Y A194611 Column 4 of A194615. %K A194611 nonn,more %O A194611 1,1 %A A194611 _R. H. Hardin_, Aug 30 2011