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A279729
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Sum of all the parts of the Goldbach partitions (p,q) of 2n such that all primes from p to q (inclusive) appear as a part in some Goldbach partition of p+q = 2n.
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5
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0, 0, 6, 8, 20, 12, 14, 0, 36, 0, 22, 72, 26, 0, 90, 0, 34, 72, 38, 0, 42, 0, 46, 0, 0, 52, 0, 0, 58, 300, 62, 0, 0, 68, 0, 0, 74, 0, 78, 0, 82, 252, 86, 0, 90, 0, 94, 0, 0, 100, 0, 0, 212, 0, 0, 112, 0, 0, 118, 240, 122, 0, 0, 128, 0, 0, 134, 0, 138, 0, 142, 144, 146, 0
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OFFSET
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1,3
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LINKS
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FORMULA
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MAPLE
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with(numtheory): A279729:=n->2*n*add((pi(i)-pi(i-1)) * (pi(2*n-i)-pi(2*n-i-1)) * (product(1-abs((pi(k)-pi(k-1))-(pi(2*n-k)-pi(2*n-k-1))), k=i..n)), i=3..n): seq(A279729(n), n=1..100);
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MATHEMATICA
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f[n_, x_: 0] := Sum[(If[x == 0, i, 2 n - i] Boole[PrimeQ@ i] Boole[PrimeQ[2 n - i]]) Product[1 - Abs[Boole[PrimeQ@ k] - Boole[PrimeQ[2 n - k]]], {k, i, n}], {i, 3, n}]; Table[f@ n + f[n, 1], {n, 100}] (* Michael De Vlieger, Dec 18 2016 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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