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A124305 Riordan array (1,2*sqrt(3)*sin(asin(3*sqrt(3)*x/2)/3)/3). 3
1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 2, 0, 1, 0, 3, 0, 3, 0, 1, 0, 0, 7, 0, 4, 0, 1, 0, 12, 0, 12, 0, 5, 0, 1, 0, 0, 30, 0, 18, 0, 6, 0, 1, 0, 55, 0, 55, 0, 25, 0, 7, 0, 1, 0, 0, 143, 0, 88, 0, 33, 0, 8, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,13

COMMENTS

Inverse of A124304. Row sums are A047749. Diagonal sums appear to be aerated version of A098746.

LINKS

Table of n, a(n) for n=0..65.

EXAMPLE

Triangle begins

.1,

.0, 1,

.0, 0, 1,

.0, 1, 0, 1,

.0, 0, 2, 0, 1,

.0, 3, 0, 3, 0, 1,

.0, 0, 7, 0, 4, 0, 1,

.0, 12, 0, 12, 0, 5, 0, 1

Contribution from Paul Barry, Sep 28 2009: (Start)

Production matrix is

0, 1,

0, 0, 1,

0, 1, 0, 1,

0, 0, 1, 0, 1,

0, 1, 0, 1, 0, 1,

0, 0, 1, 0, 1, 0, 1,

0, 1, 0, 1, 0, 1, 0, 1,

0, 0, 1, 0, 1, 0, 1, 0, 1,

0, 1, 0, 1, 0, 1, 0, 1, 0, 1,

0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1 (End)

CROSSREFS

Sequence in context: A052173 A175790 A177825 * A087073 A242411 A243055

Adjacent sequences:  A124302 A124303 A124304 * A124306 A124307 A124308

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Oct 25 2006

STATUS

approved

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Last modified October 24 09:28 EDT 2014. Contains 248516 sequences.