Number of permutations sigma of [n] such that sigma(k)/k > sigma(k+1)/(k+1) for 1 <= k <= n-1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =9a(7) =19a(8) =30a(9) =60a(10) =108a(11) =222a(12) =388a(13) =874a(14) =1601a(15) =3244a(16) =6437a(17) =14056a(18) =26545a(19) =57326a(20) =109333a(21) =232751a(22) =481137a(23) =1002039a(24) =1911740a(25) =4261276a(26) =8678424a(27) =17734328a(28) =36186279a(29) =77402058