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A138240 Expansion of (1/4)(1-sqrt(1-12x)/sqrt(1-4x)). 1
0, 1, 6, 40, 296, 2400, 20928, 192768, 1848960, 18277888, 184890368, 1904259072, 19898765312, 210424545280, 2247494172672, 24209586782208, 262696649785344, 2868744309571584, 31504024885002240, 347697247933169664 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Hankel transform of a(n) is -4^comb(n,2)*A099156(n)=-4^comb(n,2)*[x^n](x/(1-8x+4x^2)).

Hankel transform of a(n+1) is 4^comb(n+1,2)=A053763(n+1).

Hankel transform of a(n+2) is 4^comb(n+1,2)*A102591(n+1)=4^comb(n+1,2)*[x^n](6-4x)/(1-8x+4x^2).

CROSSREFS

Cf. A104498.

Sequence in context: A069720 A005037 A081337 * A083805 A181571 A006387

Adjacent sequences:  A138237 A138238 A138239 * A138241 A138242 A138243

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Mar 07 2008

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Last modified February 16 10:28 EST 2012. Contains 205904 sequences.