The On-Line Encyclopedia of Integer Sequences (OEIS)

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Revision History for A177560

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Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, down, up.
(history; published version)

#6 by Alois P. Heinz at Sat Nov 02 20:00:14 EDT 2013

STATUS

editing

approved

#5 by Alois P. Heinz at Sat Nov 02 20:00:05 EDT 2013

DATA

1, 6, 84, 2054, 78231, 4290094, 320821079, 31414709469, 3903342922319, 600255674485509, 111949642485388109, 24900064681761042208, 6512262064364063116565, 1978717544093002418592533

EXTENSIONS

a(11)-a(14) from Alois P. Heinz, Nov 02 2013

#4 by Alois P. Heinz at Sat Nov 02 19:43:32 EDT 2013

NAME

Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, down, up.

AUTHOR

R. H. Hardin , May 10 2010

STATUS

approved

editing

#3 by Russ Cox at Sat Mar 31 12:35:44 EDT 2012

AUTHOR

_R. H. Hardin (rhhardin(AT)att.net) _ May 10 2010

Discussion

Sat Mar 31

12:35

OEIS Server: https://oeis.org/edit/global/875

#2 by N. J. A. Sloane at Sat Oct 02 03:00:00 EDT 2010

KEYWORD

nonn,new

nonn

AUTHOR

Ron R. H. Hardin (rhhardin(AT)att.net) May 10 2010

#1 by N. J. A. Sloane at Tue Jun 01 03:00:00 EDT 2010

NAME

Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, down, up

DATA

1, 6, 84, 2054, 78231, 4290094, 320821079, 31414709469, 3903342922319, 600255674485509

OFFSET

1,2

KEYWORD

nonn,new

AUTHOR

Ron Hardin (rhhardin(AT)att.net) May 10 2010

STATUS

approved