A177304 Number of permutations of 6 copies of 1..n with all adjacent differences <= 1 in absolute value.

1, 1, 924, 65226, 7426610, 640160976, 54331653686, 4339892975512, 336181036999948, 25328979140590460, 1869147741803280158, 135594223551932310368, 9700134237572864570026, 685890678156217774839644, 48025674779522388568648420, 3334799454210630503054336064

Offset: 0

Author

R. H. Hardin, May 06 2010

Keywords

• nonn

Comments

a(n) = (6n)!/720^n = A248814(n) for n<=2.

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..200

Crossrefs

Column k=6 of A331562.

Cf. A248814.

Extensions

a(0)=1 prepended by Alois P. Heinz, Jan 21 2020

a(9) from Alois P. Heinz, Jan 23 2020

Terms a(10) and beyond from Andrew Howroyd, May 15 2020