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A050454
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a(n) = Sum_{d|n, d=3 mod 4} d^3.
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2
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0, 0, 27, 0, 0, 27, 343, 0, 27, 0, 1331, 27, 0, 343, 3402, 0, 0, 27, 6859, 0, 370, 1331, 12167, 27, 0, 0, 19710, 343, 0, 3402, 29791, 0, 1358, 0, 43218, 27, 0, 6859, 59346, 0, 0, 370, 79507, 1331, 3402, 12167, 103823, 27, 343, 0, 132678, 0, 0
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OFFSET
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1,3
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LINKS
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MAPLE
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A050454 := proc(n) local a, d; a := 0 ; for d in numtheory[divisors](n) do if d mod 4 = 3 then a := a+d^3 ; end if; end do; a ; end proc:
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MATHEMATICA
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a[n_] := DivisorSum[n, #^3 &, Mod[#, 4]==3 &]; Array[a, 30] (* Amiram Eldar, Dec 06 2018 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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