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 A026759 #27 Sep 08 2022 08:44:49
%S A026759 1,2,7,27,109,453,1922,8284,36155,159435,709246,3178992,14343567,
%T A026759 65099245,297015765,1361584755,6268757195,28975155915,134410918700,
%U A026759 625578384150,2920488902795,13672762887465,64179220019365,301987822527627
%N A026759 a(n) = T(2n, n), T given by A026758.
%H A026759 Vincenzo Librandi, <a href="/A026759/b026759.txt">Table of n, a(n) for n = 0..200</a>
%F A026759 a(n) = A002212(n+1) - A000245(n). - _David Callan_, Feb 01 2014
%F A026759 G.f.: ((1-x)*sqrt(1 - 4*x) - sqrt(1 - 6*x + 5*x^2))/(2*x^2). - _G. C. Greubel_, Oct 31 2019
%p A026759 seq(coeff(series(((1-x)*sqrt(1-4*x) - sqrt(1 -6*x +5*x^2))/(2*x^2), x, n+2), x, n), n = 0..30); # _G. C. Greubel_, Oct 31 2019
%t A026759 CoefficientList[Normal[Series[((1-x)Sqrt[1-4x] -Sqrt[1-6x+5x^2])/(2x^2), {x, 0, 30}]], x] (* _David Callan_, Feb 01 2014 *)
%o A026759 (PARI) my(x='x+O('x^30)); Vec(((1-x)*sqrt(1 - 4*x) - sqrt(1 - 6*x + 5*x^2))/(2*x^2)) \\ _G. C. Greubel_, Oct 31 2019
%o A026759 (Magma) R<x>:=PowerSeriesRing(Rationals(), 30); Coefficients(R!( ((1-x)*Sqrt(1 - 4*x) - Sqrt(1 - 6*x + 5*x^2))/(2*x^2) )); // _G. C. Greubel_, Oct 31 2019
%o A026759 (Sage)
%o A026759 def A077952_list(prec):
%o A026759 P.<x> = PowerSeriesRing(ZZ, prec)
%o A026759 return P(((1-x)*sqrt(1-4*x) - sqrt(1-6*x+5*x^2))/(2*x^2)).list()
%o A026759 A077952_list(30) # _G. C. Greubel_, Oct 31 2019
%Y A026759 Cf. A026758, A026760, A026761, A026762, A026763, A026764, A026765, A026766, A026767, A026768.
%K A026759 nonn
%O A026759 0,2
%A A026759 _Clark Kimberling_