%I #6 Mar 02 2016 11:27:03

%S 1,1,48620,227873431500,66341857216154520,10150867545062935511900

%N Number of permutations of 9 copies of 1..n with all adjacent differences <= 2 in absolute value.

%C a(n) = (9n)!/362880^n for n<=3.

%Y Cf. A172613.

%K nonn

%O 0,3

%A _R. H. Hardin_, May 06 2010