A284713 - OEIS

%I #27 Apr 11 2018 13:23:18

%S 1,1,3,12,56,289,1604,9415,57801,368269,2421115,16352401,113075441,

%T 798316997,5741446395,41984708298,311673028845,2345644392051,

%U 17876342623580,137820598360123,1073961913716521,8452182814380104,67136452766364121,537890721293399309

%N Number of indecomposable permutations avoiding the pattern 4231.

%H Vaclav Kotesovec, <a href="/A284713/b284713.txt">Table of n, a(n) for n = 1..50</a>

%H A. L. L. Gao, S. Kitaev, P. B. Zhang. <a href="https://arxiv.org/abs/1605.05490">On pattern avoiding indecomposable permutations</a>, arXiv:1605.05490 [math.CO], 2016.

%F G.f.: 1 - 1/g(x), where g(x) is the (at present unknown) g.f. for A061552. - _Vaclav Kotesovec_, Apr 03 2017

%Y Cf. A061552.

%K nonn

%O 1,3

%A _N. J. A. Sloane_, Apr 02 2017

%E More terms from _Vaclav Kotesovec_, Apr 03 2017

%E Name corrected by _Michael D. Weiner_, Apr 10 2018