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 A065707 #13 Aug 17 2017 05:54:21
%S A065707 0,1,-9,126,-2270,49995,-1301139,39066076,-1329148764,50536328085,
%T A065707 -2123542798685,97722882268506,-4887863677728954,264025383760041631,
%U A065707 -15317578742680490535,949914821498248213560,-62707584375936061905464,4390358319593012839913001
%N A065707 Bessel polynomial {y_n}'(-2).
%D A065707 J. Riordan, Combinatorial Identities, Wiley, 1968, p. 77.
%H A065707 G. C. Greubel, <a href="/A065707/b065707.txt">Table of n, a(n) for n = 0..360</a>
%H A065707 <a href="/index/Be#Bessel">Index entries for sequences related to Bessel functions or polynomials</a>
%F A065707 From _G. C. Greubel_, Aug 14 2017: (Start)
%F A065707 a(n) = 2*n*(1/2)_{n}*(-4)^(n - 1)* hypergeometric1f1(1 - n, -2*n, -1).
%F A065707 E.g.f.: ((1 + 4*x)^(3/2) - 2*x*(1 + 4*x)^(1/2) - 1)* exp((sqrt(1 + 4*x) -1)/2)/(4*(1 + 4*x)^(3/2)). (End)
%F A065707 G.f.: (x/(1-x)^3)*hypergeometric2f0(2,3/2; - ; -4*x/(1-x)^2). - _G. C. Greubel_, Aug 16 2017
%t A065707 Join[{0}, Table[2*n*Pochhammer[1/2, n]*(-4)^(n - 1)*Hypergeometric1F1[1 - n, -2*n, -1], {n, 1, 50}]] (* _G. C. Greubel_, Aug 14 2017 *)
%o A065707 (PARI) for(n=0,50, print1(sum(k=0,n-1, (n+k+1)!/(2*(n-k-1)!*k!)), ", ")) \\ _G. C. Greubel_, Aug 14 2017
%Y A065707 Cf. A001514, A065920, A065921, A065922, A065707, A006199.
%K A065707 sign
%O A065707 0,3
%A A065707 _N. J. A. Sloane_, Dec 08 2001