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A050451
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a(n) = Sum_{d|n, d=1 mod 4} d^3.
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3
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1, 1, 1, 1, 126, 1, 1, 1, 730, 126, 1, 1, 2198, 1, 126, 1, 4914, 730, 1, 126, 9262, 1, 1, 1, 15751, 2198, 730, 1, 24390, 126, 1, 1, 35938, 4914, 126, 730, 50654, 1, 2198, 126, 68922, 9262, 1, 1, 91980, 1, 1, 1, 117650, 15751, 4914, 2198, 148878
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OFFSET
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1,5
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LINKS
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MAPLE
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A050451 := proc(n) local a, d; a := 0 ; for d in numtheory[divisors](n) do if d mod 4 = 1 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]==1 &]; 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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