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A297795
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a(n) = Sum_{d|n} min(d, n/d)^5.
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5
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1, 2, 2, 34, 2, 66, 2, 66, 245, 66, 2, 552, 2, 66, 488, 1090, 2, 552, 2, 2114, 488, 66, 2, 2600, 3127, 66, 488, 2114, 2, 6802, 2, 2114, 488, 66, 6252, 10376, 2, 66, 488, 8364, 2, 16104, 2, 2114, 6738, 66, 2, 18152, 16809, 6316, 488, 2114, 2, 16104, 6252, 35728, 488
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = - Sum_{k in Z} (k^4-3*n*k^2+n^2)*H(4*n-k^2) where H() is the Hurwitz class number.
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MATHEMATICA
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f[n_] := Block[{d = Divisors@n}, Plus @@ (Min[#, n/#]^5 & /@ d)]; Array[f, 57] (* Robert G. Wilson v, Jan 06 2018 *)
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PROG
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(PARI) {a(n) = sumdiv(n, d, min(d, n/d)^5)}
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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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