Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #10 Jul 02 2019 02:56:03
%S 1,1,1,3,12,36,126,666,6588,44892,237996,2204676,26370576,219140208,
%T 1720782792,19941776856,234038005776,2243409386256,23225205107088,
%U 295070141019312,4303459657780416,55200265166477376,660776587455193056
%N Number of degree-n even permutations of order dividing 6.
%H Alois P. Heinz, <a href="/A061130/b061130.txt">Table of n, a(n) for n = 0..522</a>
%H 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 E.g.f.: 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 Cf. A000085, A001470, A001472, A052501, A053496 - A053505, A001189, A001471, A001473, A061121 - A061128, A000704, A061129 - A061132, A048099, A051695, A061133 - A061135.
%K easy,nonn
%O 0,4
%A _Vladeta Jovovic_, Apr 14 2001