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A104629 Expansion of (1-2x-sqrt(1-4x))/(1+2x+sqrt(1-4x))/x^2. 3
1, 2, 6, 18, 57, 186, 622, 2120, 7338, 25724, 91144, 325878, 1174281, 4260282, 15548694, 57048048, 210295326, 778483932, 2892818244, 10786724388, 40347919626, 151355847012, 569274150156, 2146336125648, 8110508473252 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Diagonal sums of A039598. a(n)=A000957(n+3).

FORMULA

a(n)=(1+sum{k=0..n+2, C(k)(-2)^k})/(8(-2)^n)

CROSSREFS

Cf. A064310.

Sequence in context: A125306 A064310 A126983 * A000957 A125305 A148458

Adjacent sequences:  A104626 A104627 A104628 * A104630 A104631 A104632

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Mar 17 2005

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Last modified February 16 17:48 EST 2012. Contains 205939 sequences.