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%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
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