A177299 Number of permutations of 4 copies of 1..n with all adjacent differences <= 2 in absolute value.

1, 70, 34650, 4635540, 439192790, 51023044582, 5712786772130, 590059992663400

Offset

1,2

Comments

a(n)=(4n)!/24^n for n<=3

Links

Table of n, a(n) for n=1..8.

Crossrefs

Sequence in context: A177673 A177661 A177672 * A266740 A177640 A177641

Adjacent sequences: A177296 A177297 A177298 * A177300 A177301 A177302

Keyword

nonn

Author

R. H. Hardin May 06 2010

Status

approved