%I #15 May 16 2020 01:34:20

%S 1,1,48620,60110030,161686253810,304100156874800,574996024253854586,

%T 1016915629343040544250,1745708356607370063330620,

%U 2911820015993491302722966990,4754502826758413615581742528138,7626389809822483147908697112197520,12055478550658617275428327115583119762

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

%C a(n) = (9n)!/362880^n = A172613(n) for n<=2.

%H Andrew Howroyd, <a href="/A177313/b177313.txt">Table of n, a(n) for n = 0..200</a>

%Y Column k=9 of A331562.

%Y Cf. A172613.

%K nonn

%O 0,3

%A _R. H. Hardin_, May 06 2010

%E a(0)=1 prepended by _Alois P. Heinz_, Jan 20 2020

%E Terms a(7) and beyond from _Andrew Howroyd_, May 15 2020