Number of permutations of [n] with no ascending runs of length 1 or 2.

A186735

Number of permutations of [n] with no ascending runs of length 1 or 2.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =20a(7) =69a(8) =180a(9) =1930a(10) =12611a(11) =61051a(12) =566129a(13) =5179750a(14) =38348469a(15) =376547340a(16) =4169246332a(17) =41559058969a(18) =465750294781

External references