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 A061133 #4 May 10 2013 12:44:45 %S A061133 0,0,0,0,0,0,210,5040,37800,201600,2044350,25530120,213993780, %T A061133 1692490800,19767998250,232823791200,2235629476080,23171222430720, %U A061133 294649445112750,4300403589581400,55176842335916700,660577269463243440 %N A061133 Number of degree-n even permutations of order exactly 6. %F A061133 E.g.f.: exp(x) - 1/2*exp(x + 1/2*x^2) - 1/2*exp(x - 1/2*x^2) - exp(x + 1/3*x^3) + 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 A061133 Cf. A000085, A001470, A001472, A052501, A053496 - A053505, A001189, A001471, A001473, A061121 - A061128, A000704, A061129 - A061132, A048099, A051695, A061133 - A061135. %K A061133 easy,nonn %O A061133 1,7 %A A061133 _Vladeta Jovovic_, Apr 14 2001