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A090879
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Sum_{d|n} d*2^(n-d).
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0
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1, 4, 7, 20, 21, 94, 71, 328, 457, 1194, 1035, 7052, 4109, 17294, 33807, 83984, 65553, 389650, 262163, 1484820, 1949717, 4216854, 4194327, 29409304, 22020121, 67215386, 119799835, 350453788, 268435485, 1755807774, 1073741855
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| G.f.: Sum_{m>0} m*x^m/(1-(2*x)^m).
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MATHEMATICA
| f[n_] := Block[{d = Divisors[n]}, Apply[Plus, d*2^(n - d)]]; Table[ f[n], {n, 1, 32}] (from Robert G. Wilson v Feb 16 2004)
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CROSSREFS
| Cf. A074854, A083413.
Sequence in context: A133264 A127415 A045548 * A084404 A147065 A049947
Adjacent sequences: A090876 A090877 A090878 * A090880 A090881 A090882
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KEYWORD
| easy,nonn
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AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 14 2004
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 16 2004
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