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 A186215 #6 Jul 22 2025 10:19:50 %S A186215 15055,2008031,116461359,9406230423,660028898887,49524283508081, %T A186215 3611859394076247 %N A186215 Number of (n+1)X6 0..2 arrays with every 2X2 subblock determinant equal to some horizontal or vertical neighbor 2X2 subblock determinant. %C A186215 Column 5 of A186218 %e A186215 Some solutions for 3X6 %e A186215 ..0..0..2..0..1..0....0..0..1..0..0..0....0..0..1..1..0..1....0..0..0..1..0..0 %e A186215 ..0..0..0..0..0..0....0..0..0..0..0..2....0..0..0..0..0..0....0..0..0..0..0..0 %e A186215 ..0..0..0..0..2..2....0..0..2..1..0..2....0..1..1..1..1..0....2..0..2..0..2..1 %K A186215 nonn %O A186215 1,1 %A A186215 _R. H. Hardin_ Feb 15 2011