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Search: id:A124391
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| A124391 |
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Numbers n that divide A123269(n) = Sum[ i^j^k, {i,1,n}, {j,1,n}, {k,1,n} ]. |
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3
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| 1, 2, 3, 4, 6, 7, 8, 9, 11, 12, 14, 16, 18, 20, 21, 22, 23, 24, 27, 28, 31, 32, 33, 36, 40, 42, 43, 44, 46, 47, 48, 49, 54, 56, 59, 60, 62, 63, 64, 66, 67, 69, 71, 72, 77, 79, 80, 81, 83, 84, 86, 88, 92, 93, 94, 96, 98, 99, 100, 103
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OFFSET
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1,2
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COMMENT
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A123269(n) = Sum[ i^j^k, {i,1,n}, {j,1,n}, {k,1,n} ] = {1, 28, 7625731729896, ...}. Primes in a(n) are {2, 3, 7, 11, 23, 31, 43, 47, 59, 67, 71, 79, 83, 103, ...} = A039787(n) Primes p such that p-1 is square-free.
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MATHEMATICA
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Do[f=Sum[Mod[Sum[Mod[Sum[PowerMod[i, j^k, n], {i, 1, n}], n], {j, 1, n}], n], {k, 1, n}]; If[IntegerQ[f/n], Print[n]], {n, 1, 103}]
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CROSSREFS
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Cf. A123269, A039787, A086787.
Sequence in context: A050126 A013939 A004144 this_sequence A050118 A081754 A004436
Adjacent sequences: A124388 A124389 A124390 this_sequence A124392 A124393 A124394
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KEYWORD
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hard,more,nonn
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AUTHOR
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Alexander Adamchuk (alex(AT)kolmogorov.com), Oct 30 2006
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