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A281863
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Alternating powers of 60 and 10 times powers of 60.
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4
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1, 10, 60, 600, 3600, 36000, 216000, 2160000, 12960000, 129600000, 777600000, 7776000000, 46656000000, 466560000000, 2799360000000, 27993600000000, 167961600000000, 1679616000000000, 10077696000000000, 100776960000000000, 604661760000000000
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OFFSET
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0,2
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COMMENTS
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These numbers are the values for the positions in the sumerian (and babylonian) alternating sexagesimal - decimal system (used at least up to 10*60^2 = 36000, but here extended).
For the numbers in this mixed base system see A055643. For the number of symbols needed for representing n see A131650. For the number of digits (including 0) of the representation of n see A282622.
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REFERENCES
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Georges Ifrah, Universalgeschichte der Zahlen, Campus Verlag, Frankfurt, New York, 2. Auflage, 1987, pp.210-221.
Histoire Universelle des Chiffres, Paris, 1981.
From one to zero, A universal history of numbers, Viking Penguin Inc., 1985.
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LINKS
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FORMULA
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a(2*n) = 60^(n/2), a(2*n+1) = 10*60^((n-1)/2), n >= 0.
a(n) = 60*a(n-2) for n>1.
G.f.: (1 + 10*x) / (1 - 60*x^2).
(End)
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MATHEMATICA
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LinearRecurrence[{0, 60}, {1, 10}, 21] (* or *) a[0]=1; a[1]=10; a[n_]:=60*a[n-2]; Table[a[n], {n, 0, 20}] (* Indranil Ghosh, Feb 21 2017 *)
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PROG
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(PARI) Vec((1 + 10*x) / (1 - 60*x^2) + O(x^30)) \\ Colin Barker, Feb 21 2017
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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