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 A281602 #4 Jan 25 2017 10:38:42 %S A281602 30,442,8180,167545,3401430,69506779,1421127262,29066686772, %T A281602 594539026170,12161158312943,248754881654232,5088256100638530, %U A281602 104079805217582244,2128942973242332029,43547336604707609360,890756851949851865902 %N A281602 Number of nX5 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors and with new values introduced in order 0 sequentially upwards. %C A281602 Column 5 of A281605. %H A281602 R. H. Hardin, <a href="/A281602/b281602.txt">Table of n, a(n) for n = 1..210</a> %F A281602 Empirical: a(n) = 24*a(n-1) -47*a(n-2) -552*a(n-3) +408*a(n-4) +3664*a(n-5) +11951*a(n-6) +4496*a(n-7) -51712*a(n-8) -608027*a(n-9) +618602*a(n-10) +3874985*a(n-11) -3781199*a(n-12) -16785095*a(n-13) +11073712*a(n-14) +71617473*a(n-15) -132533827*a(n-16) +121433498*a(n-17) -95249752*a(n-18) +148536078*a(n-19) -176780273*a(n-20) -59040921*a(n-21) +269285969*a(n-22) -308246859*a(n-23) +159030948*a(n-24) -64978465*a(n-25) +40730650*a(n-26) +67888637*a(n-27) -98865108*a(n-28) +15454808*a(n-29) +69306797*a(n-30) -40262490*a(n-31) -40951058*a(n-32) +48761392*a(n-33) -12747670*a(n-34) -7345822*a(n-35) +6634632*a(n-36) -1752064*a(n-37) +175688*a(n-38) -11428*a(n-39) -792*a(n-40) for n>42 %e A281602 Some solutions for n=4 %e A281602 ..0..1..1..0..2. .0..1..0..1..2. .0..1..2..0..2. .0..1..0..2..0 %e A281602 ..2..0..2..0..2. .0..1..2..1..0. .1..0..2..1..2. .0..2..0..1..0 %e A281602 ..2..0..1..0..2. .0..1..0..1..0. .1..0..2..0..0. .1..1..0..1..2 %e A281602 ..2..1..2..0..1. .2..1..2..2..0. .2..0..1..1..2. .0..2..2..1..0 %Y A281602 Cf. A281605. %K A281602 nonn %O A281602 1,1 %A A281602 _R. H. Hardin_, Jan 25 2017