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A318937
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a(n) = 16 times the sum of the cubes of the divisors of 2*n+1.
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1
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16, 448, 2016, 5504, 12112, 21312, 35168, 56448, 78624, 109760, 154112, 194688, 252016, 327040, 390240, 476672, 596736, 693504, 810464, 984704, 1102752, 1272128, 1526112, 1661184, 1887888, 2201472, 2382048, 2685312, 3073280, 3286080, 3631712, 4166528, 4431168, 4812224
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OFFSET
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0,1
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LINKS
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FORMULA
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Sum_{k=0..n} a(k) ~ 30*zeta(4) * n^4. - Amiram Eldar, Dec 12 2023
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MAPLE
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with(numtheory);
rJ0 := proc(k) local n, d; n:=2*k+1; 16*add(d^3, d in divisors(n)); end;
[seq(rJ0(k), k=0..60)];
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MATHEMATICA
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PROG
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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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