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A158495 Expansion of ((1-4x)+sqrt(1-4x))/(2(1-2x)). 2


%S 1,-1,-3,-8,-21,-56,-154,-440,-1309,-4048,-12958,-42712,-144210,

%T -496432,-1735764,-6145968,-21986781,-79331232,-288307254,-1054253208,

%U -3875769606,-14315659632,-53097586284,-197677736208,-738415086066

%N Expansion of ((1-4x)+sqrt(1-4x))/(2(1-2x)).

%C Hankel transform is A158496.

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

%F Conjecture: n*a(n) +6*(-n+1)*a(n-1) +4*(2*n-3)*a(n-2)=0. - _R. J. Mathar_, Dec 03 2014

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

%K easy,sign

%O 0,3

%A _Paul Barry_, Mar 20 2009

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Last modified January 19 12:36 EST 2020. Contains 331049 sequences. (Running on oeis4.)