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 A061132 #18 Jul 02 2019 02:56:27
%S A061132 1,1,1,1,4,40,190,610,1660,13420,174700,1326700,30818800,342140800,
%T A061132 2534931400,16519411000,143752426000,4842417082000,73620307162000,
%U A061132 687934401562000,17165461784680000,308493094924720000,4585953613991980000,53843602355379220000
%N A061132 Number of degree-n even permutations of order dividing 10.
%D A061132 J. Riordan, An Introduction to Combinatorial Analysis, John Wiley & Sons, Inc. New York, 1958 (Chap 4, Problem 22).
%H A061132 Alois P. Heinz, <a href="/A061132/b061132.txt">Table of n, a(n) for n = 0..491</a>
%H A061132 Lev Glebsky, Melany Licón, Luis Manuel Rivera, <a href="https://arxiv.org/abs/1907.00548">On the number of even roots of permutations</a>, arXiv:1907.00548 [math.CO], 2019.
%F A061132 E.g.f.: 1/2*exp(x + 1/2*x^2 + 1/5*x^5 + 1/10*x^10) + 1/2*exp(x - 1/2*x^2 + 1/5*x^5 - 1/10*x^10).
%e A061132 For n=4 the a(4)=4 solutions are (1), (1, 2)(3, 4), (1, 3)(2, 4), (1, 4)(2, 3) (permutations in cyclic notation). - _Luis Manuel Rivera Martínez_, Jun 18 2019
%t A061132 With[{nn = 22}, CoefficientList[Series[1/2 Exp[x + x^2/2 + x^5/5 + x^10/10] + 1/2 Exp[x - x^2/2 + x^5/5 - x^10/10], {x, 0, nn}], x]* Range[0, nn]!] (* _Luis Manuel Rivera Martínez_, Jun 18 2019 *)
%o A061132 (PARI) my(x='x+O('x^25)); Vec(serlaplace(1/2*exp(x + 1/2*x^2 + 1/5*x^5 + 1/10*x^10) + 1/2*exp(x - 1/2*x^2 + 1/5*x^5 - 1/10*x^10))) \\ _Michel Marcus_, Jun 18 2019
%Y A061132 Cf. A000085, A001470, A001472, A052501, A053496-A053505, A001189, A001471, A001473, A061121-A061128, A000704, A061129-A061132, A048099, A051695, A061133-A061135.
%K A061132 easy,nonn
%O A061132 0,5
%A A061132 _Vladeta Jovovic_, Apr 14 2001