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A141343 Riordan array (1,x/sqrt(2-sqrt(1+4x)). 2
1, 0, 1, 0, 2, 1, 0, 2, 4, 1, 0, 4, 8, 6, 1, 0, 2, 16, 18, 8, 1, 0, 12, 24, 44, 32, 10, 1, 0, -12, 48, 90, 96, 50, 12, 1, 0, 72, 48, 180, 240, 180, 72, 14, 1, 0, -190, 160, 308, 544, 530, 304, 98, 16, 1, 0, 700, -40, 600, 1120, 1372, 1032, 476, 128 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,5

COMMENTS

Factorises as (1,xc(-x))*(1,x(1+x)/(1-2x)) where c(x) is the g.f. of A000108.

Row sums are A141344.

Triangle T(n,k), 0<=k<=n, read by rows, given by [0, 2, -1, -1, -1, -1, -1, -1, -1, ...] DELTA [1, 0, 0, 0, 0, 0, 0, ...] where DELTA is the operator defined in A084938 . [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 15 2008]

EXAMPLE

Triangle begins

1,

0, 1,

0, 2, 1,

0, 2, 4, 1,

0, 4, 8, 6, 1,

0, 2, 16, 18, 8, 1,

0, 12, 24, 44, 32, 10, 1,

0, -12, 48, 90, 96, 50, 12, 1

CROSSREFS

Sequence in context: A204163 A122542 A098542 * A066709 A174026 A108354

Adjacent sequences:  A141340 A141341 A141342 * A141344 A141345 A141346

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Jun 26 2008

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Last modified February 17 10:57 EST 2012. Contains 206009 sequences.