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.

A055640 Number of nonzero digits in decimal expansion of n.

Original entry on oeis.org

0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2
Offset: 0

Views

Author

Henry Bottomley, Jun 06 2000

Keywords

Comments

Comment from Antti Karttunen, Sep 05 2004: (Start)
Also number of characters needed to write the number n in classical Greek alphabetic system, up to n=999. The Greek alphabetic system assigned values to the letters as follows:
alpha = 1, beta = 2, gamma = 3, delta = 4, epsilon = 5, digamma = 6, zeta = 7, eta = 8, theta = 9, iota = 10, kappa = 20, lambda = 30, mu = 40, nu = 50, xi = 60, omicron = 70, pi = 80, koppa = 90, rho = 100, sigma = 200, tau = 300, upsilon = 400, phi = 500, chi = 600, psi = 700, omega = 800, sampi = 900. (End)
For partial sums see A102685. - Hieronymus Fischer, Jun 06 2012

Examples

			129 is written as rho kappa theta in the old Greek system.
		

References

  • L. Threatte, The Greek Alphabet, in The World's Writing Systems, edited by Peter T. Daniels and William Bright, Oxford Univ. Press, 1996, p. 278.

Crossrefs

Differs from A098378 for the first time at position n=200 with a(200)=1, as only one nonzero Arabic digit (and only one Greek letter) is needed for two hundred, while A098378(200)=2 as two characters are needed in the Ethiopic system.

Programs

Formula

From Hieronymus Fischer, Jun 06 2012: (Start)
a(n) = Sum_{j=1..m+1} (floor(n/10^j+0.9) - floor(n/10^j)), where m = floor(log_10(n)).
a(n) = m + 1 - A055641(n).
G.f.: (1/(1-x))*Sum_{j>=0} (x^10^j - x^(10*10^j))/(1-x^10^(j+1)). (End)
a(n) = A055642(n) - A055641(n).

A098476 Unicode codes for the lunation runes, used in certain medieval Scandinavian perpetual calendar staves as golden numbers 1-19.

Original entry on oeis.org

5792, 5794, 5798, 5805, 5809, 5812, 5820, 5823, 5825, 5830, 5835, 5839, 5842, 5850, 5848, 5862, 5870, 5871, 5872
Offset: 1

Views

Author

Antti Karttunen, Sep 10 2004

Keywords

Comments

This order of runes with these graphic forms is used in many rune staves in the collections of the National Museum of Finland. Note that the first sixteen of them make up the so-called younger futhark (runic alphabet), but with the fourteenth and fifteenth runes (codes 5850 and 5848, i.e. ᛚ ᛚ (L) ᛘ ᛘ (M)) having swapped their places from the usual m-l order:
ᚠ (F), ᚢ (U), ᚦ (Th), ᚭ (O), ᚱ (R), ᚴ (K), ᚼ (H), ᚿ (N), ᛁ (I), ᛆ (A), ᛋ (S), ᛏ (T), ᛒ (B), ᛚ (L), ᛘ (M), ᛦ (Y); or, using html character entities:
ᚠ (F), ᚢ (U), ᚦ (Th), ᚭ (O), ᚱ (R), ᚴ (K), ᚼ (H), ᚿ (N),
ᛁ (I), ᛆ (A), ᛋ (S), ᛏ (T), ᛒ (B), ᛚ (L), ᛘ (M), ᛦ (Y).
The last three lunation runes were ligatures, coined to make up the full 1-19 set: ᛮ ᛮ (ARLAUG), ᛯ ᛯ (TVIMADUR), ᛰ ᛰ (BELGTHOR).

References

  • R. W. V. Elliott, Runes: An Introduction, St Martin's Press; 2nd edition, 1989.
  • R. W. V. Elliott, The Runic Script, in The World's Writing Systems, edited by Peter T. Daniels and William Bright, Oxford Univ. Press, 1996. p. 333-339.

Crossrefs

A327894 Unicode codes for digit characters in the Basic Multilingual Plane (BMP).

Original entry on oeis.org

48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 1632, 1633, 1634, 1635, 1636, 1637, 1638, 1639, 1640, 1641, 1776, 1777, 1778, 1779, 1780, 1781, 1782, 1783, 1784, 1785, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 2406, 2407, 2408, 2409, 2410, 2411, 2412, 2413, 2414, 2415, 2534
Offset: 1

Views

Author

Alonso del Arte, Sep 29 2019

Keywords

Comments

A digit is a character in a given Unicode block that can be combined with other digits in that same Unicode block to form zero-padded nonnegative integers in a positional number base, which can then be sorted arithmetically according to their Unicode values.
That's not the case for numerals, such as for example Roman Numeral Ten (U+2169), nor ASCII letters used as Roman numerals. For example, XIV, XVI, XIX would be sorted as XIV, XIX, XVI (14, 19, 16, rather than 14, 16, 19).
This listing does not include digit characters in the BMP Private Use Area, such as, for example, Klingon Digit Zero (U+F8F0, corresponding to 63728) as assigned by ConScript.
Unicode consistently assigns digit characters so that the code point modulo 16 corresponds to the numerical value of the digit, so that digit zero is U+xxx0 and digit nine is U+xxx9.
Except for the digits for Indian languages and the Limbu language, which are assigned so that the code point modulo 16 corresponds to the numerical value of the digit plus 6 (thus digit zero is U+xxx6 and digit nine is U+xxxF).
This is a principle that ConScript for the most part follows, such as for example with Klingon and Ferengi. Perhaps the only exception is U+E033, Tengwar Letter Stemless Vilya which also serves as Tengwar Digit One. Interestingly, however, take note of Tengwar Duodecimal Digit Ten (U+E06A) and Tengwar Duodecimal Digit Eleven (U+E06B).
The largest number that could theoretically be in this sequence is 65535. There are digits in the supplementary planes, e.g. Osmanya Digit Zero, U+104A0, giving a theoretical maximum of 1114111.
However, since the assignment of the supplementary planes is ongoing for many years to come, to include those in this entry might require occasional insertions. Computation of that sequence would pose only one minor and easily solved problem for Java's isDigit() function, though.
On the other hand, the assignment of Arabic Extended-B (U+0870 through U+089F) has not been finalized yet, though that proposal contains neither digits nor numerals.
Also, no proposal nor suggestion has been made for U+2FE0 through U+2FEF, so there is a small chance those could be assigned digits.

Examples

			The following digits zero are encoded in the BMP (excluding Private Use Area).
U+0030 (48) [ISO-LATIN-1] Digit Zero
U+0660 (1632) Arabic-Indic Digit Zero
U+06F0 (1776) Extended Arabic-Indic Digit Zero
U+07C0 (1984) Nko Digit Zero
U+0966 (2406) Devanagari Digit Zero
U+09E6 (2534) Bengali Digit Zero
U+0A66 (2662) Gurmukhi Digit Zero
U+0AE6 (2790) Gujarati Digit Zero
U+0B66 (2918) Oriya Digit Zero
U+0BE6 (3046) Tamil Digit Zero
U+0C66 (3174) Telugu Digit Zero
U+0CE6 (3302) Kannada Digit Zero
U+0D66 (3430) Malayalam Digit Zero
U+0E50 (3664) Thai Digit Zero
U+0ED0 (3792) Lao Digit Zero
U+0F20 (3872) Tibetan Digit Zero
U+1040 (4160) Myanmar Digit Zero
U+1090 (4240) Myanmar Shan Digit Zero
U+17E0 (6112) Khmer Digit Zero
U+1810 (6160) Mongolian Digit Zero
U+1946 (6470) Limbu Digit Zero
U+19D0 (6608) New Tai Lue Digit Zero
U+1A80 (6784) Tai Tham Hora Digit Zero
U+1A90 (6800) Tai Tham Tham Digit Zero
U+1B50 (6992) Balinese Digit Zero
U+1BB0 (7088) Sundanese Digit Zero
U+1C40 (7232) Lepcha Digit Zero
U+1C50 (7248) Ol Chiki Digit Zero
U+A620 (42528) Vai Digit Zero
U+A8D0 (43216) Saurashtra Digit Zero
U+A900 (43264) Kayah Li Digit Zero
U+A9D0 (43472) Javanese Digit Zero
U+AA50 (43600) Cham Digit Zero
U+ABF0 (44016) Meetei Mayek Digit Zero
U+FF10 (65296) Fullwidth Digit Zero
Although U+3007, Ideographic Number Zero, from the CJK Symbols & Punctuation block, does have an associated numeric value of 0, it returns false for isDigit(). Thus 12295 is not included in this sequence.
		

Crossrefs

Programs

  • Scala
    (0 to 65535).filter(_.toChar.isDigit)
Showing 1-3 of 3 results.