A177299 - OEIS

%I #3 Mar 31 2012 12:35:42

%S 1,70,34650,4635540,439192790,51023044582,5712786772130,

%T 590059992663400

%N Number of permutations of 4 copies of 1..n with all adjacent differences <= 2 in absolute value.

%C a(n)=(4n)!/24^n for n<=3

%K nonn

%O 1,2

%A _R. H. Hardin_ May 06 2010