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A102360
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a(n) = sigma((7^n - 1)/6), where sigma(n) is the sum of positive divisors of n.
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1
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1, 15, 80, 961, 2802, 52800, 142020, 2347506, 10512320, 96837120, 329849040, 8619170560, 16148168402, 221483030400, 1146781040640, 14442767744328, 38774519976900, 813898294809600, 1904350030969680, 35410174950039552
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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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PROG
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Feb 22 2005
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STATUS
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approved
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