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 A232339 #6 Jul 23 2025 07:19:36 %S A232339 1,110,1282,3472,38986,117690,1274656,4158066,42080048,146531864, %T A232339 1393415694,5138181574,46239884144,179337779938,1537326888338, %U A232339 6234688975144,51199303984118,216023027477120,1707858843212112 %N A232339 Number of 5Xn 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally or antidiagonally, with no adjacent elements equal. %C A232339 Row 5 of A232335 %H A232339 R. H. Hardin, <a href="/A232339/b232339.txt">Table of n, a(n) for n = 1..210</a> %F A232339 Empirical: a(n) = a(n-1) +32*a(n-2) -17*a(n-3) -3*a(n-4) -162*a(n-5) -178*a(n-6) +240*a(n-7) -47*a(n-8) +1633*a(n-9) -1527*a(n-10) +1816*a(n-11) -5806*a(n-12) +4608*a(n-13) -5834*a(n-14) +12194*a(n-15) -8388*a(n-16) +10308*a(n-17) -17052*a(n-18) +9996*a(n-19) -11795*a(n-20) +16635*a(n-21) -7989*a(n-22) +9086*a(n-23) -11378*a(n-24) +4230*a(n-25) -4661*a(n-26) +5307*a(n-27) -1415*a(n-28) +1514*a(n-29) -1589*a(n-30) +269*a(n-31) -279*a(n-32) +272*a(n-33) -22*a(n-34) +22*a(n-35) -20*a(n-36) for n>42 %e A232339 Some solutions for n=5 %e A232339 ..0..1..0..1..0....2..1..2..1..2....0..1..2..1..0....1..2..0..1..2 %e A232339 ..2..1..2..1..2....2..1..0..1..0....2..1..2..1..2....0..1..2..0..2 %e A232339 ..0..1..0..1..0....0..2..0..1..0....2..1..2..1..0....2..0..1..0..1 %e A232339 ..0..1..2..1..2....0..1..2..1..0....2..1..0..1..2....1..2..1..2..1 %e A232339 ..0..1..2..1..2....2..1..2..1..2....2..1..0..1..2....1..2..1..0..2 %K A232339 nonn %O A232339 1,2 %A A232339 _R. H. Hardin_, Nov 22 2013