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A024385 a(n) = [ (2nd elementary symmetric function of S(n))/(first elementary symmetric function of S(n)) ], where S(n) = {first n+1 positive integers congruent to 1 mod 4}. 0

%I

%S 0,3,9,16,25,36,49,64,82,101,122,145,170,197,227,258,291,326,363,402,

%T 444,487,532,579,628,679,733,788,845,904,965,1028,1094,1161,1230,1301,

%U 1374,1449,1527,1606,1687,1770,1855,1942

%N a(n) = [ (2nd elementary symmetric function of S(n))/(first elementary symmetric function of S(n)) ], where S(n) = {first n+1 positive integers congruent to 1 mod 4}.

%F Conjecture: a(n) = 2*a(n-1) - a(n-2) + a(n-6) - 2*a(n-7) + a(n-8). G.f. x^2*(-3-3*x-x^2-2*x^3-2*x^4-2*x^5+x^6) / ( (1+x)*(1+x+x^2)*(x^2-x+1)*(x-1)^3 ). - _R. J. Mathar_, Oct 08 2011

%F a(n) = floor(A024378(n) / A000384(n+1)). - _Sean A. Irvine_, Jul 06 2019

%K nonn

%O 1,2

%A _Clark Kimberling_

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Last modified July 8 19:20 EDT 2020. Contains 335524 sequences. (Running on oeis4.)