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 A061139 #4 May 10 2013 12:44:45 %S A061139 0,0,0,0,0,20,240,1260,5600,45360,383040,2451680,17128320,157769040, %T A061139 1902380480,18882623760,163633317120,2095059774080,30792478993920, %U A061139 346562329685760,3905491275514880,58609449249207360,866031730098205440 %N A061139 Number of degree-n odd permutations of order exactly 6. %F A061139 E.g.f.: - 1/2*exp(x + 1/2*x^2) + 1/2*exp(x - 1/2*x^2) + 1/2*exp(x + 1/2*x^2 + 1/3*x^3 + 1/6*x^6) - 1/2*exp(x - 1/2*x^2 + 1/3*x^3 - 1/6*x^6). %Y A061139 Cf. A000085, A001470, A001472, A052501, A053496 - A053505, A001189, A001471, A001473, A061121 - A061128, A000704, A061129 - A061132, A048099, A051695, A061133 - A061135, A001465, A061136 - A061140. %K A061139 easy,nonn %O A061139 0,6 %A A061139 _Vladeta Jovovic_, Apr 14 2001