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A281863 Alternating powers of 60 and 10 times powers of 60. 4
1, 10, 60, 600, 3600, 36000, 216000, 2160000, 12960000, 129600000, 777600000, 7776000000, 46656000000, 466560000000, 2799360000000, 27993600000000, 167961600000000, 1679616000000000, 10077696000000000, 100776960000000000, 604661760000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

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.

REFERENCES

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.

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0,60).

FORMULA

a(2*n) = 60^(n/2), a(2*n+1) = 10*60^((n-1)/2), n >= 0.

From Colin Barker, Feb 21 2017: (Start)

a(n) = 60*a(n-2) for n>1.

G.f.: (1 + 10*x) / (1 - 60*x^2).

(End)

MATHEMATICA

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 *)

PROG

(PARI) Vec((1 + 10*x) / (1 - 60*x^2) + O(x^30)) \\ Colin Barker, Feb 21 2017

CROSSREFS

Cf. A131650, A055643, A282622.

Sequence in context: A002493 A054364 A004309 * A219368 A052664 A090373

Adjacent sequences:  A281860 A281861 A281862 * A281864 A281865 A281866

KEYWORD

nonn,easy,changed

AUTHOR

Wolfdieter Lang, Feb 19 2017

STATUS

approved

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Last modified January 18 20:19 EST 2018. Contains 297865 sequences.