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!)
A028283 Central elements in 4-Pascal triangle A028275 (by row). 1
1, 4, 10, 32, 110, 392, 1428, 5280, 19734, 74360, 281996, 1074944, 4115020, 15808912, 60917800, 235350720, 911315430, 3535767000, 13742347740, 53495534400, 208537056420, 813950932080, 3180614712600, 12441628655040 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Equals A000984, [1, 2, 6, 20, 70,...] convolved with [1, 2, 0, 0, 0,...]. [From Gary W. Adamson, Jun 05 2009]

LINKS

Table of n, a(n) for n=0..23.

FORMULA

C(n)*(6n-2), where C(n) are the Catalan numbers (A000108). - Ralf Stephan, Aug 24 2003

CROSSREFS

Twice A051960.

Sequence in context: A033297 A129880 A137954 * A196991 A151746 A110145

Adjacent sequences:  A028280 A028281 A028282 * A028284 A028285 A028286

KEYWORD

nonn

AUTHOR

Mohammad K. Azarian

EXTENSIONS

More terms from James A. Sellers

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 November 27 23:10 EST 2014. Contains 250286 sequences.