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A089284
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Number of divisors of floor(pi*10^n), pi=3.14...
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2
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2, 2, 4, 6, 8, 2, 8, 8, 48, 8, 16, 4, 8, 8, 8, 8, 72, 4, 64, 96, 16, 64, 128, 128, 8, 24, 256, 8, 32, 64, 16, 64, 192, 4, 24, 40, 96, 2, 32, 4, 16, 48, 8, 32, 16, 64, 48, 8, 320, 8, 32, 48, 8, 64, 192, 48, 16, 32, 16, 64, 96, 128, 8, 120, 16, 64, 32, 48, 8, 32, 192, 512, 64, 96, 144
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| a(n)=A000005(A011545(n)).
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LINKS
| Dario Alejandro Alpern, Factorization using the Elliptic Curve Method.
Hisanori Mishima, Decimal expansions of pi (n = 0 to 100).
Hisanori Mishima, Decimal expansions of pi (n = 101 to 200).
Hisanori Mishima, Decimal expansions of pi (n = 201 to 250).
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EXAMPLE
| n=4: floor(pi*10^4)=31415 with divisors: {1,5,61,103,305,515,6283,31415}: a(4)=8.
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MATHEMATICA
| Table[ DivisorSigma[ 0, Floor[ Pi*10^n]], {n, 0, 10}] (From Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 30 2003)
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CROSSREFS
| Cf. A089282, A089283, A000796.
Sequence in context: A145804 A046639 A178702 * A081488 A199117 A194695
Adjacent sequences: A089281 A089282 A089283 * A089285 A089286 A089287
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KEYWORD
| nonn
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AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 30 2003
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com) and Ray Chandler (rayjchandler(AT)sbcglobal.net), Oct 30, 2003
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