The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A174072 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A174072

Number of permutations of length n with no consecutive triples i,i+2,i+4.
(history; published version)

#37 by OEIS Server at Sun Feb 04 14:15:46 EST 2024

LINKS

Max Alekseyev, <a href="/A174072/b174072_1.txt">Table of n, a(n) for n = 0..100</a>

#36 by Max Alekseyev at Sun Feb 04 14:15:46 EST 2024

STATUS

editing

approved

Discussion

Sun Feb 04

14:15

OEIS Server: Installed first b-file as b174072.txt.

#35 by Max Alekseyev at Sun Feb 04 14:14:02 EST 2024

LINKS

Max Alekseyev, <a href="/A174072/b174072_1.txt">Table of n, a(n) for n = 0..100</a>

STATUS

approved

editing

#34 by Alois P. Heinz at Wed Mar 02 09:13:01 EST 2022

STATUS

proposed

approved

#33 by Jean-François Alcover at Wed Mar 02 04:42:23 EST 2022

STATUS

editing

proposed

#32 by Jean-François Alcover at Wed Mar 02 04:42:19 EST 2022

MATHEMATICA

b[s_, x_, y_] := b[s, x, y] = If[s == {}, 1, Sum[

If[x == 0 || x - y != 2 || y - j != 2,

b[s ~Complement~ {j}, y, j], 0], {j, s}]];

a[n_] := b[Range[n], 0, 0];

Table[a[n], {n, 0, 14}] (* Jean-François Alcover, Mar 02 2022, after Alois P. Heinz *)

STATUS

approved

editing

#31 by Alois P. Heinz at Thu Apr 22 10:43:54 EDT 2021

STATUS

editing

approved

#30 by Alois P. Heinz at Thu Apr 22 10:43:49 EDT 2021

REFERENCES

Wayne M. Dymacek, Isaac Lambert and Kyle Parsons, Arithmetic Progressions in Permutations, http://math.ku.edu/~ilambert/CN.pdf, 2012.

LINKS

Wayne M. Dymacek, Isaac Lambert and Kyle Parsons, <a href="http://math.ku.edu/~ilambert/CN.pdf">Arithmetic Progressions in Permutations</a>, 2012. [broken link]

STATUS

approved

editing

#29 by Alois P. Heinz at Thu Apr 22 10:41:51 EDT 2021

STATUS

editing

approved

#28 by Alois P. Heinz at Thu Apr 22 05:11:52 EDT 2021

DATA

1, 1, 2, 6, 24, 114, 674, 4714, 37754, 340404, 3412176, 37631268, 452745470, 5900431012, 82802497682, 1244815252434, 19958707407096, 339960096280062, 6130407887839754, 116675071758609742, 2337186717333367706, 49153251967227002616, 1082860432463176004544

KEYWORD

nonn,more,changed

EXTENSIONS

a(12)-a(2122) from Alois P. Heinz, Apr 13 2021

Discussion

Thu Apr 22

05:12

Alois P. Heinz: data section full ...