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A158495 Expansion of ((1-4x)+sqrt(1-4x))/(2(1-2x)). 2
1, -1, -3, -8, -21, -56, -154, -440, -1309, -4048, -12958, -42712, -144210, -496432, -1735764, -6145968, -21986781, -79331232, -288307254, -1054253208, -3875769606, -14315659632, -53097586284, -197677736208, -738415086066 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Hankel transform is A158496.

LINKS

Table of n, a(n) for n=0..24.

FORMULA

a(n) = (2*0^n + A126966(n) - 2^n)/2.

Conjecture: n*a(n) +6*(-n+1)*a(n-1) +4*(2*n-3)*a(n-2)=0. - R. J. Mathar, Dec 03 2014

MATHEMATICA

CoefficientList[Series[((1-4x)+Sqrt[1-4x])/(2(1-2x)), {x, 0, 30}], x] (* Harvey P. Dale, Dec 15 2011 *)

CROSSREFS

Essentially the same as A014318, up to sign and offset.

Cf. A126966, A158496.

Sequence in context: A008909 A006835 A014318 * A273720 A018037 A018038

Adjacent sequences:  A158492 A158493 A158494 * A158496 A158497 A158498

KEYWORD

easy,sign,changed

AUTHOR

Paul Barry, Mar 20 2009

STATUS

approved

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Last modified September 28 13:24 EDT 2020. Contains 337393 sequences. (Running on oeis4.)