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 A260346 #13 Aug 02 2015 14:58:57 %S A260346 0,0,1,4,22,124,706,3968,21880,118192,625776,3251744,16610072, %T A260346 83537520,414288080,2028760544,9822006896,47063458528,223408338400, %U A260346 1051514839104,4910856580376,22772597352944,104914684398352,480457417780320,2188115766353616,9914318477830304,44708936142838816 %N A260346 Expansion of x^2*((1 - 12*x + 50*x^2 - 76*x^3 + 42*x^4 - 48*x^5 + 32*x^6)/(1 - 4*x)^4 + 4*x^2/(1 - 4*x)^(5/2)). %H A260346 I. G. Enting and A. J. Guttmann, <a href="http://dx.doi.org/10.1088/0305-4470/22/14/013">Area-weighted moments of convex polygons on the square lattice</a>, J. Phys. A 22 (1989), 2639-2642. See Eq. (4). %F A260346 G.f.: x^2*((1 - 12*x + 50*x^2 - 76*x^3 + 42*x^4 - 48*x^5 + 32*x^6)/(1 - 4*x)^4 + 4*x^2/(1 - 4*x)^(5/2)). %p A260346 t1:=x^2*( (1-12*x+50*x^2-76*x^3+42*x^4-48*x^5+32*x^6)/(1-4*x)^4 + 4*x^2/(1-4*x)^(5/2)); %p A260346 series(t1,x,40); %p A260346 seriestolist(%); %Y A260346 Cf. A005436. %K A260346 nonn %O A260346 0,4 %A A260346 _N. J. A. Sloane_, Aug 02 2015