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A238096 Sum_{k=2..n} floor(n/k)*floor((tau(k)+1)/2), where tau = A000005. 2


%S 0,1,2,5,6,10,11,16,19,23,24,33,34,38,42,50,51,60,61,70,74,78,79,94,

%T 97,101,106,115,116,129,130,141,145,149,153,172,173,177,181,196,197,

%U 210,211,220,229,233,234,257,260,269,273,282,283,298,302,317,321,325,326,353,354,358,367,382,386,399,400,409,413,426

%N Sum_{k=2..n} floor(n/k)*floor((tau(k)+1)/2), where tau = A000005.

%C Number of quadratic polynomials with coefficients from {1..n} for which both roots are integers.

%C A generalization of A006318.

%D D. Andrica and E. J. Ionascu, On the number of polynomials with coefficients in [n], An. St. Univ. Ovidius Constanta, 2013, to appear.

%Y Cf. A000005, A006318, A238097, A238098.

%K nonn

%O 1,3

%A _N. J. A. Sloane_, Feb 22 2014

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Last modified September 16 18:26 EDT 2021. Contains 347473 sequences. (Running on oeis4.)