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A105201 Number of compositions of n such that the least part occurs with even multiplicity. 2

%I

%S 0,1,0,5,3,16,23,64,102,251,464,999,1920,4023,7910,16154,32059,64894,

%T 129368,260319,520057,1043669,2086532,4180928,8361875,16741659,

%U 33486337,67014046,134043807,268184694,536423635,1073080023,2146330624

%N Number of compositions of n such that the least part occurs with even multiplicity.

%F G.f.: Sum(Sum(binomial(k, 2*l)*x^(2*k-2*l)/((1-x)^(k-2*l)*(1-x^k)), l=1..floor(k/2)), k=1..infinity).

%t CoefficientList[ Series[ Sum[ Binomial[k, 2l] x^(2k - 2l)/((1 - x)^(k - 2*l)(1 - x^k)), {k, 34}, {l, Floor[k/2]}], {x, 0, 34}], x] (from _Robert G. Wilson v_, Apr 12 2005)

%Y Cf. A096374.

%K easy,nonn

%O 1,4

%A _Vladeta Jovovic_, Apr 12 2005

%E More terms from _Robert G. Wilson v_, Apr 12 2005

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Last modified November 22 08:48 EST 2014. Contains 249805 sequences.