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 A321244 #36 Sep 08 2022 08:46:23
%S A321244 0,2,69,1572,19865,153480,830802,3476144,12003462,35757630,94780235,
%T A321244 228579252,509929719,1065625652,2106541920,3969848640,7176749852,
%U A321244 12509692794,21113614017,34626453860,55344881445,86431928352,132174030494,198295824432,292341936450,424135940150,606327641127,855040875444,1190635082147,1638595028940
%N A321244 Non-isomorphic proper colorings of the 3 X 3 grid graph using at most n colors under rotational and reflectional symmetries.
%D A321244 F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, 1973.
%H A321244 Colin Barker, <a href="/A321244/b321244.txt">Table of n, a(n) for n = 1..1000</a>
%H A321244 Marko Riedel et al., <a href="https://math.stackexchange.com/questions/2584928/">Tree graphs colorings</a>, Math StackExchange, December 2017.
%H A321244 Marko Riedel et al., <a href="https://math.stackexchange.com/questions/2977453/">3-colourings of a 3×3 table with one of 3 colors up to symmetries</a>, Math StackExchange, October 2018.
%H A321244 Marko Riedel, <a href="/A321244/a321244.maple.txt">Maple code for OCP computation by Burnside.</a>
%H A321244 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (10,-45,120,-210,252,-210,120,-45,10,-1).
%F A321244 a(n) = (1/8)*n^9 - (3/2)*n^8 + (33/4)*n^7 - (53/2)*n^6 + (217/4)*n^5 - (291/4)*n^4 + (507/8)*n^3 - (133/4)*n^2 + 8*n.
%F A321244 From _Colin Barker_, Nov 01 2018: (Start)
%F A321244 G.f.: x^2*(2 + 49*x + 972*x^2 + 7010*x^3 + 17710*x^4 + 15273*x^5 + 4076*x^6 + 268*x^7) / (1 - x)^10.
%F A321244 a(n) = 10*a(n-1) - 45*a(n-2) + 120*a(n-3) - 210*a(n-4) + 252*a(n-5) - 210*a(n-6) + 120*a(n-7) - 45*a(n-8) + 10*a(n-9) - a(n-10) for n>10.
%F A321244 (End)
%t A321244 CoefficientList[Series[x (2 + 49 x + 972 x^2 + 7010 x^3 + 17710 x^4 + 15273 x^5 + 4076 x^6 + 268 x^7) / (1 - x)^10, {x, 0, 30}], x] (* _Vincenzo Librandi_ Nov 04 2018 *)
%o A321244 (PARI) concat(0, Vec(x^2*(2 + 49*x + 972*x^2 + 7010*x^3 + 17710*x^4 + 15273*x^5 + 4076*x^6 + 268*x^7) / (1 - x)^10 + O(x^30))) \\ _Colin Barker_, Nov 01 2018
%o A321244 (Magma) [(1/8)*n^9-(3/2)*n^8+(33/4)*n^7-(53/2)*n^6+(217/4)*n^5-(291/4)*n^4 +(507/8)*n^3-(133/4)*n^2+8*n: n in [1..30]]; // _Vincenzo Librandi_, Nov 04 2018
%Y A321244 Cf. A002817, A321245, A321246.
%K A321244 nonn,easy
%O A321244 1,2
%A A321244 _Marko Riedel_, Nov 01 2018