cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A055643 Babylonian numbers: integers in base 60 with each sexagesimal digit represented by 2 decimal digits, leading zeros omitted.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110
Offset: 0

Views

Author

Henry Bottomley, Jun 06 2000

Keywords

Comments

From Wolfdieter Lang, Jan 16 2018: (Start)
The symbols used for 0..9 in this base 60 notation are 00, 01, ..., 09, but leading zeros are omitted.
For the Sumerian-Babylonian sexagesimal-decimal number system which uses two positions for each base-60 position filled with only one-digit numbers alternating between ranges of 0 to 9 and 0 to 5 see the link below.
(End)
For n < 1440, US and NATO military time designation of n minutes since midnight. - J. Lowell, Dec 29 2020

References

  • Mohammad K. Azarian, Meftah al-hesab: A Summary, MJMS, Vol. 12, No. 2, Spring 2000, pp. 75-95. Mathematical Reviews, MR 1 764 526. Zentralblatt MATH, Zbl 1036.01002.
  • Mohammad K. Azarian, A Summary of Mathematical Works of Ghiyath ud-din Jamshid Kashani, Journal of Recreational Mathematics, Vol. 29(1), pp. 32-42, 1998.
  • Georges Ifrah, Histoire Universelle des Chiffres, Paris, 1981.
  • Georges Ifrah, From one to zero, A universal history of numbers, Viking Penguin Inc., 1985.
  • Georges Ifrah, Universalgeschichte der Zahlen, Campus Verlag, Frankfurt, New York, 2. Auflage, 1987, pp. 210-221.

Crossrefs

Note also that A250073 = a(A000079(n)), A250089 = a(A051037(n)), A254334 = a(A000244(n)), A254335 = a(A000351(n)), A254336 = a(A011557(n)).
See also A281863 (value of the 0,1,2,...,n-th digit of a(n), counted from the right), A282622 (length of a(n), #digits, for n >= 1).

Programs

  • Mathematica
    Array[FromDigits@ Apply[Join, PadLeft[#, 2] & /@ IntegerDigits@ IntegerDigits[#, 60]] &, 71, 0] (* Michael De Vlieger, Jan 11 2018 *)
  • PARI
    A055643(n)=fromdigits(digits(n,60),100) \\ M. F. Hasler, Jan 09 2018
    
  • Python
    def a(n): return n if n < 60 else 100*a(n//60) + n%60
    print([a(n) for n in range(71)]) # Michael S. Branicky, Oct 22 2022

Formula

a(60*n+r) = 100*a(n) + r, 0 <= r <= 59. - Jianing Song, Oct 22 2022

Extensions

a(69) and a(70) from WG Zeist, Sep 08 2012

A281863 Alternating powers of 60 and 10 times powers of 60.

Original entry on oeis.org

1, 10, 60, 600, 3600, 36000, 216000, 2160000, 12960000, 129600000, 777600000, 7776000000, 46656000000, 466560000000, 2799360000000, 27993600000000, 167961600000000, 1679616000000000, 10077696000000000, 100776960000000000, 604661760000000000
Offset: 0

Views

Author

Wolfdieter Lang, Feb 19 2017

Keywords

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, Histoire Universelle des Chiffres, Paris, 1981.
  • Georges Ifrah, From one to zero, A universal history of numbers, Viking Penguin Inc., 1985.
  • Georges Ifrah, Universalgeschichte der Zahlen, Campus Verlag, Frankfurt, New York, 2. Auflage, 1987, pp. 210-221.
  • David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987. See p. 127.

Crossrefs

Programs

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

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)
E.g.f.: cosh(2*sqrt(15)*x) + sqrt(5/3)*sinh(2*sqrt(15)*x). - Stefano Spezia, Sep 08 2024

A131650 Number of symbols in Babylonian numeral representation of n.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 3, 4
Offset: 1

Views

Author

Alain Van Kerckhoven (alain(AT)avk.org), Sep 10 2007

Keywords

Comments

From Wolfdieter Lang, Feb 21 2017: (Start)
For a(1)..a(59) this sequence coincides with A007953.
For the sexagesimal - decimal representation of n see A055643.
The values of the positions is given in A281863.
The sum of the digits of A055643(n) = a(n).
The number of digits of the representation of n is given in A282622. (End)

Crossrefs

Extensions

More terms from Michel Marcus, Jul 12 2013
Terms a(60)-a(81) from Wolfdieter Lang, Feb 21 2017 (to distinguish it from A007953)
Showing 1-3 of 3 results.