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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

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Last modified August 28 03:16 EDT 2015. Contains 261112 sequences.