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A177321
Number of permutations of n copies of 1..9 with all adjacent differences <= 1 in absolute value.
2
1, 2, 416, 664958, 1792874048, 6232521421502, 25328979140590460, 114573118435555703030, 560523113474283819256640, 2911820015993491302722966990, 15861703283168731825003935183416, 89796737967084981726163781067177194, 524830705066715697873367329722967841532
OFFSET
0,2
LINKS
CROSSREFS
Row n=9 of A331562.
Sequence in context: A349764 A153911 A259562 * A365520 A080392 A154541
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