A177321 Number of permutations of n copies of 1..9 with all adjacent differences <= 1 in absolute value.

1, 2, 416, 664958, 1792874048, 6232521421502, 25328979140590460, 114573118435555703030, 560523113474283819256640, 2911820015993491302722966990, 15861703283168731825003935183416, 89796737967084981726163781067177194, 524830705066715697873367329722967841532

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..100

Crossrefs

Row n=9 of A331562.

Sequence in context: A349764 A153911 A259562 * A365520 A080392 A154541

Adjacent sequences: A177318 A177319 A177320 * A177322 A177323 A177324

Keyword

nonn

Author

R. H. Hardin, May 06 2010

Extensions

a(0)=1 prepended by Alois P. Heinz, Jan 20 2020

Terms a(6) and beyond from Andrew Howroyd, May 15 2020

Status

approved