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A110754
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a(n) = tau(N), where N = the number obtained as a concatenation of 8712 with itself n times and tau(n) = number of divisors of n.
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2
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36, 144, 768, 576, 1152, 6144, 2304, 18432, 15360, 18432, 12288, 49152, 4608, 36864, 6291456, 294912, 9216, 983040, 576, 294912, 18874368, 196608
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OFFSET
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1,1
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COMMENTS
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8712 has the property that any number of concatenation of it with self and the digit reversal have same prime divisors.
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LINKS
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Table of n, a(n) for n=1..22.
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FORMULA
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a(n)=A000005[8712*sum_{i=0..n-1} 10^(4i)] . - R. J. Mathar, Aug 17 2007
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EXAMPLE
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a(2) =tau(87128712) = 144.
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MAPLE
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A110754 := proc(n) local pow8712, i ; pow8712 := 8712*add(10^(4*i), i=0..n-1) ; numtheory[tau](pow8712) ; end: seq(A110754(n), n=1..22) ; - R. J. Mathar, Aug 17 2007
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CROSSREFS
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Cf. A110751, A110752, A110753.
Sequence in context: A119767 A016910 A005017 * A154711 A162992 A037072
Adjacent sequences: A110751 A110752 A110753 * A110755 A110756 A110757
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KEYWORD
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base,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Aug 11 2005
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EXTENSIONS
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More terms from R. J. Mathar, Aug 17 2007
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STATUS
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approved
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