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 A194783 #6 Jul 22 2025 12:36:42 %S A194783 23,219,1641,11686,84727,639325,5044981,41614291,358184223,3210665949, %T A194783 29914282858,289187619416 %N A194783 Number of lower triangles of a (2n+3)X(2n+3) 0..n array with new values introduced in row major order 0..n and no element unequal to more than one horizontal or vertical neighbor. %C A194783 Row 5 of A194778 %e A194783 Some solutions for n=2 containing a 2 %e A194783 ..0..............0..............0..............0..............0 %e A194783 ..1.1............1.1............1.1............0.0............1.1 %e A194783 ..1.1.2..........1.1.1..........1.1.1..........0.0.0..........1.1.1 %e A194783 ..1.1.2.2........1.1.1.1........1.1.1.1........0.0.0.0........2.2.2.2 %e A194783 ..1.1.2.2.2......1.1.1.1.1......1.1.1.1.1......0.0.0.0.1......2.2.2.2.1 %e A194783 ..1.1.2.2.2.2....2.2.2.2.2.2....2.2.2.2.2.2....0.0.0.0.1.1....2.2.2.2.1.1 %e A194783 ..1.1.2.2.2.2.2..2.2.2.2.2.2.2..2.2.2.2.2.2.1..0.0.0.0.1.1.2..2.2.2.2.1.1.0 %K A194783 nonn %O A194783 1,1 %A A194783 _R. H. Hardin_ Sep 02 2011