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 A001880 M4989 N2146 #36 Jan 10 2018 19:04:08
%S A001880 1,15,210,3150,51975,945945,18918900,413513100,9820936125,
%T A001880 252070693875,6957151150950,205552193096250,6474894082531875,
%U A001880 216659917377028125,7675951358500425000,287080580807915895000,11303797869311688365625,467445288360359818884375
%N A001880 Coefficients of Bessel polynomials y_n (x).
%D A001880 J. Riordan, Combinatorial Identities, Wiley, 1968, p. 77.
%D A001880 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A001880 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A001880 T. D. Noe, <a href="/A001880/b001880.txt">Table of n, a(n) for n = 4..100</a>
%H A001880 Selden Crary, Richard Diehl Martinez, Michael Saunders, <a href="https://arxiv.org/abs/1707.00705">The Nu Class of Low-Degree-Truncated Rational Multifunctions. Ib. Integrals of Matern-correlation functions for all odd-half-integer class parameters</a>, arXiv:1707.00705 [stat.ME], 2017, Table 1.
%H A001880 J. Riordan, <a href="/A001820/a001820.pdf">Notes to N. J. A. Sloane, Jul. 1968</a>
%H A001880 <a href="/index/Be#Bessel">Index entries for sequences related to Bessel functions or polynomials</a>
%F A001880 E.g.f.: x*(1 + x/2)/(1 - 2*x)^(7/2); or, if shifted, (1+ 6x+ 3x^2/2!) / (1-2x)^(9/2).
%F A001880 a(n) = (2*n-4)!/(4!*(n-4)!*2^(n-4)).
%F A001880 (n-4)*a(n) = (n-2)*(2*n-5)*a(n-1) for n = 5, 6, .. , with a(4) = 1. - _Johannes W. Meijer_, May 24 2009
%F A001880 G.f.: x^4*2F0(5/2,3;;2x). - _R. J. Mathar_, Aug 08 2015
%t A001880 nn = 25; t = Range[0, nn]! CoefficientList[Series[x (1 + x/2)/(1 - 2 x)^(7/2), {x, 0, nn}], x]; Drop[t, 1] (* _T. D. Noe_, Aug 10 2012 *)
%o A001880 (PARI) x='x+O('x^50); Vec(serlaplace(x*(1 + x/2)/(1 - 2*x)^(7/2))) \\ _G. C. Greubel_, Aug 13 2017
%Y A001880 See A001518.
%Y A001880 Column 4 of triangle A001497.
%Y A001880 Equals the second right hand column of the triangles A094665 and A083061.
%Y A001880 Other right hand columns are A001147, A160470, A160471 and A160472.
%K A001880 nonn,easy
%O A001880 4,2
%A A001880 _N. J. A. Sloane_