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A047877 a(n) = (1/2)*Sum_{i=0..n} T(i,n-i), array T as in A049604. 0

%I

%S 0,3,4,4,6,9,11,14,18,21,26,32,34,41,49,52,59,69,73,82,92,97,108,120,

%T 124,137,151,156,169,185,191,206,222,229,246,264,270,289,309,316,335,

%U 357,365,386,408,417,440,464,472,497,523

%N a(n) = (1/2)*Sum_{i=0..n} T(i,n-i), array T as in A049604.

%F From _Chai Wah Wu_, Jun 11 2016: (Start)

%F a(n) = 2*a(n-3) + a(n-4) - a(n-6) - 2*a(n-7) + a(n-10) for n > 14 (conjectured).

%F G.f.: x*(x^13 + x^11 - x^9 - 2*x^8 - 4*x^7 - x^6 + x^5 + 2*x^4 - 4*x^2 - 4*x - 3)/(x^10 - 2*x^7 - x^6 + x^4 + 2*x^3 - 1) (conjectured). (End)

%K nonn

%O 0,2

%A _Clark Kimberling_

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Last modified January 20 23:16 EST 2020. Contains 331104 sequences. (Running on oeis4.)