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A138828
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Sum of digits of n-th even perfect number.
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1
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6, 10, 19, 19, 28, 64, 55, 73, 190, 235, 289, 352, 1405, 1711, 3520, 5833, 5968, 8821, 11548, 11791, 26317, 27298, 30232, 53740, 58960, 62956, 120898, 233722, 299314, 356860, 585478, 2048248, 2329372, 3405232, 3789352, 8056495, 8186041, 18894079, 36485416, 56880973, 65115946, 70334902, 82384129
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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a[n_] := Block[{e, p, mpe = MersennePrimeExponent@n}, Plus @@ IntegerDigits[(2^mpe - 1) 2^(mpe - 1)]]; Array[a, 44] (* Robert G. Wilson v, Aug 06 2018 *)
Total[IntegerDigits[#]]&/@Table[PerfectNumber[n], {n, 43}] (* Requires Mathematica version 10 or later *) (* The program may take a long time to run *) (* Harvey P. Dale, Feb 07 2019 *)
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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Definition changed (inserting the word "even") and a(39)-a(43) added by Ivan Panchenko, Aug 06 2018
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STATUS
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approved
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