Number of ascent sequences of length n with exactly three flat steps.

A242156

Number of ascent sequences of length n with exactly three flat steps.

Terms

    a(0) =1a(1) =4a(2) =20a(3) =100a(4) =560a(5) =3416a(6) =22764a(7) =164640a(8) =1286175a(9) =10800460a(10) =97064396a(11) =929872944a(12) =9461716810a(13) =101926129200

External references