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 A158981 #13 Sep 08 2022 08:45:43
%S A158981 1,4,-82,-1112,19660,514544,-7575224,-332852768,3865192592,
%T A158981 276417340480,-2303430504224,-280102715687296,1362687220804288,
%U A158981 334851542531477248,-396657349178753920,-461002945749901799936,-1260925479706838937344,717808917017018666550272
%N A158981 Numerator of Hermite(n, 2/7).
%H A158981 G. C. Greubel, <a href="/A158981/b158981.txt">Table of n, a(n) for n = 0..450</a>
%F A158981 From _G. C. Greubel_, Jul 10 2018: (Start)
%F A158981 a(n) = 7^n * Hermite(n, 2/7).
%F A158981 E.g.f.: exp(4*x - 49*x^2).
%F A158981 a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(4/7)^(n-2*k)/(k!*(n-2*k)!)). (End)
%t A158981 Numerator[Table[HermiteH[n,2/7],{n,0,50}]] (* _Vladimir Joseph Stephan Orlovsky_, Apr 01 2011*)
%t A158981 Table[7^n*HermiteH[n, 2/7], {n,0,50}] (* _G. C. Greubel_, Jul 10 2018 *)
%o A158981 (PARI) a(n)=numerator(polhermite(n,2/7)) \\ _Charles R Greathouse IV_, Jan 29 2016
%o A158981 (Magma) [Numerator((&+[(-1)^k*Factorial(n)*(4/7)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // _G. C. Greubel_, Jul 10 2018
%Y A158981 Cf. A158980.
%K A158981 sign,frac
%O A158981 0,2
%A A158981 _N. J. A. Sloane_, Nov 12 2009