%I #13 May 16 2020 01:34:10

%S 1,1,12870,6077196,5650739930,3772321496064,2514046004253110,

%T 1570273521448103668,951645881858020642746,560523113474283819256640,

%U 323221203836407773725200718,183122229346363470922528553652,102256611847518844993947706000234

%N Number of permutations of 8 copies of 1..n with all adjacent differences <= 1 in absolute value.

%C a(n) = (8n)!/40320^n = A172609(n) for n<=2.

%H Andrew Howroyd, <a href="/A177310/b177310.txt">Table of n, a(n) for n = 0..200</a>

%Y Column k=8 of A331562.

%Y Cf. A172609.

%K nonn

%O 0,3

%A _R. H. Hardin_, May 06 2010

%E a(0)=1 prepended by _Alois P. Heinz_, Jan 21 2020

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