A249392 - OEIS

%I #14 Mar 08 2024 18:13:33

%S 1,1,0,0,0,0,0,0,0,0,1,32,1088,17280,293832,4004352,57687080,

%T 773838336,10900027949,151388845568,2200665880514,32321771402240,

%U 495575856116168,7760560549644288,126552637539515688

%N The number of down-up permutations of [n] where adjacent elements differ by at least 5.

%Y Cf. A245377 (at least 2), A249390 (at least 3), A249391 (at least 4), A249393 (at least 6), A179958 (non-alternating)

%K nonn,more

%O 0,12

%A _R. J. Mathar_, Oct 27 2014

%E a(17)-a(21) from _Alois P. Heinz_, Oct 27 2014

%E a(22)-a(24) from _Max Alekseyev_, Feb 24 2024