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A076721
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Difference between product of divisors of n and sum of divisors of n.
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1
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0, -1, -1, 1, -1, 24, -1, 49, 14, 82, -1, 1700, -1, 172, 201, 993, -1, 5793, -1, 7958, 409, 448, -1, 331716, 94, 634, 689, 21896, -1, 809928, -1, 32705, 1041, 1102, 1177, 10077605, -1, 1384, 1465, 2559910, -1, 3111600, -1, 85100, 91047, 2044, -1, 254803844, 286, 124907
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OFFSET
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1,6
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COMMENTS
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a(p)=-1 iff p is a prime.
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LINKS
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MATHEMATICA
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Table[d = Divisors[n]; Apply[Times, d] - Apply[Plus, d], {n, 1, 50}]
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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Emrehan Halici (emrehan(AT)halici.com.tr), Oct 27 2002
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EXTENSIONS
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STATUS
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approved
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