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 A186553 #7 Jul 22 2025 10:24:33 %S A186553 0,290,290,2972,19016,2972,168200,1279862,1279862,168200,3090668, %T A186553 88662978,177942264,88662978,3090668,111188198,6215002266,31976088817, %U A186553 31976088817,6215002266,111188198,2585394080,435599518160,5253540132125 %N A186553 T(n,k)=1/8192 the number of (n+2)X(k+2) 0..3 arrays with each 3X3 subblock trace equal to some horizontal or vertical neighbor 3X3 subblock trace. %C A186553 Table starts %C A186553 ...........0..............290.................2972................168200 %C A186553 .........290............19016..............1279862..............88662978 %C A186553 ........2972..........1279862............177942264...........31976088817 %C A186553 ......168200.........88662978..........31976088817........13544245035035 %C A186553 .....3090668.......6215002266........5253540132125......5541254050323697 %C A186553 ...111188198.....435599518160......891778365437358...2292090739550640497 %C A186553 ..2585394080...30577245619492...149628929202973235.945658119457845662613 %C A186553 .78931270418.2145961447892386.25212444270769802733 %H A186553 R. H. Hardin, <a href="/A186553/b186553.txt">Table of n, a(n) for n = 1..59</a> %e A186553 Some solutions for 5X4 %e A186553 ..0..2..0..0....0..2..0..0....2..2..0..0....0..2..0..0....0..2..0..0 %e A186553 ..0..2..0..0....2..0..0..0....0..0..0..0....2..2..0..0....0..0..0..0 %e A186553 ..3..2..0..0....1..0..2..0....1..0..0..0....3..3..0..0....2..2..2..0 %e A186553 ..0..2..0..0....0..1..1..1....0..2..3..3....0..0..0..2....0..0..1..2 %e A186553 ..0..0..0..3....2..2..1..2....2..3..0..0....2..2..2..1....0..1..1..1 %K A186553 nonn,tabl %O A186553 1,2 %A A186553 _R. H. Hardin_ Feb 23 2011