A284713 Number of indecomposable permutations avoiding the pattern 4231.

1, 1, 3, 12, 56, 289, 1604, 9415, 57801, 368269, 2421115, 16352401, 113075441, 798316997, 5741446395, 41984708298, 311673028845, 2345644392051, 17876342623580, 137820598360123, 1073961913716521, 8452182814380104, 67136452766364121, 537890721293399309

Offset: 1

Author

N. J. A. Sloane, Apr 02 2017

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 1..50
• A. L. L. Gao, S. Kitaev, P. B. Zhang. On pattern avoiding indecomposable permutations, arXiv:1605.05490 [math.CO], 2016.

Crossrefs

Cf. A061552.

Formula

G.f.: 1 - 1/g(x), where g(x) is the (at present unknown) g.f. for A061552. - Vaclav Kotesovec, Apr 03 2017

Extensions

More terms from Vaclav Kotesovec, Apr 03 2017

Name corrected by Michael D. Weiner, Apr 10 2018