login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A090665 Triangle read by rows: T(n,k) = number of preferential arrangements of n things beginning with k. 0
1, 2, 1, 6, 5, 2, 26, 25, 18, 6, 150, 149, 134, 84, 24, 1082, 1081, 1050, 870, 480, 120, 9366, 9365, 9302, 8700, 6600, 3240, 720, 94586, 94585, 94458, 92526, 82320, 57120, 25200, 5040, 1091670, 1091669, 1091414, 1085364, 1038744, 871920, 554400, 221760, 40320 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The rows are the reverses of the rows of A054255.

Row sums give A000670.

Column 1 is A000629. - Joerg Arndt, Dec 08 2014

LINKS

Table of n, a(n) for n=0..44.

EXAMPLE

Triangle starts:

01: 1;

02: 2, 1;

03: 6, 5, 2;

04: 26, 25, 18, 6;

05: 150, 149, 134, 84, 24;

06: 1082, 1081, 1050, 870, 480, 120;

07: 9366, 9365, 9302, 8700, 6600, 3240, 720;

08: 94586, 94585, 94458, 92526, 82320, 57120, 25200, 5040;

09: 1091670, 1091669, 1091414, 1085364, 1038744, 871920, 554400, 221760, 40320;

10: 14174522, 14174521, 14174010, 14155350, 13950720, 12930120, 10190880, 5957280, 2177280, 362880;

...

PROG

The program is written in a variant of APL called J, a product of JSoftware. Since so few people know J, I'll not display the functions used to produce the sequence.

CROSSREFS

Cf. A054255, A008277, A028246.

Sequence in context: A113381 A228175 A118980 * A021826 A159927 A176443

Adjacent sequences:  A090662 A090663 A090664 * A090666 A090667 A090668

KEYWORD

nonn,tabl,changed

AUTHOR

Eugene McDonnell (eemcd(AT)mac.com), Dec 16 2003

EXTENSIONS

Corrected by Alois P. Heinz, Dec 08 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified December 22 12:40 EST 2014. Contains 252356 sequences.