Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A002391
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A002391 Decimal expansion of natural logarithm of 3.
(Formerly M4595 N1960)
+0
10
1, 0, 9, 8, 6, 1, 2, 2, 8, 8, 6, 6, 8, 1, 0, 9, 6, 9, 1, 3, 9, 5, 2, 4, 5, 2, 3, 6, 9, 2, 2, 5, 2, 5, 7, 0, 4, 6, 4, 7, 4, 9, 0, 5, 5, 7, 8, 2, 2, 7, 4, 9, 4, 5, 1, 7, 3, 4, 6, 9, 4, 3, 3, 3, 6, 3, 7, 4, 9, 4 (list; cons; graph; listen)
OFFSET

1,3

COMMENT

Two BBP-type Formulas are provided in http://www.mathworld.wolfram.com/BBP-TypeFormula.html Also here is Alexander Povolotsky's alternative formula for ln(3), which is not listed in http://www.mathworld.wolfram.com/BBP-TypeFormula.html ln(3) = 1/4*(1+ Sum((1/(9)^(k+1))*(27/(2*k+1) + 4/(2*k+2) + 1/(2*k+3)), k = 0 .. infinity) ) [From Alexander R. Povolotsky (pevnev(AT)juno.com), Dec 01 2008]

REFERENCES

W. E. Mansell, Tables of Natural and Common Logarithms. Royal Society Mathematical Tables, Vol. 8, Cambridge Univ. Press, 1964, p. 2.

Uhler, Horace S.; Recalculation and extension of the modulus and of the logarithms of 2, 3, 5, 7 and 17. Proc. Nat. Acad. Sci. U. S. A. 26, (1940). 205-212.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,20000

D. H. Bailey, Compendium to BBP formulas

G. Huvent, Formules BBP en base 3 [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Oct 12 2009]

S. Plouffe, Plouffe's Inverter, The natural logarithm of 3 to 10000 digits

S. Plouffe, log(3), natural logarithm of 3 to 2000 places

S. Ramanujan, Notebook entry

FORMULA

Another formula from and by Alexander R. Povolotsky ln(3) = 4/5 +2/10*sum((1/4)^n*(1/(2*n+1)+1/(2*n+3)),n=0...infinity) [From Alexander R. Povolotsky (pevnev(AT)juno.com), Dec 18 2008]

ln(3)=sum((1/9)^(k+1)(9/(2k+1)+1/(2k+2)),k=0..infinity) [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Dec 22 2008]

Sum_{i>=1} 1/(9^i*i) + Sum_{i>=0} 1/(9^i*(i+1/2)) = 2ln3 (Huvent 2001) [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Oct 12 2009]

EXAMPLE

1.098612288668109691395245236922525704647490557822749451734694333637494... [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 16 2009]

PROGRAM

(PARI) { default(realprecision, 20080); x=log(3); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b002391.txt", n, " ", d)); } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 16 2009]

CROSSREFS

Cf. A058962, A154920, A002162. [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Jan 29 2009]

Cf. A016731 Continued fraction. [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 16 2009]

Sequence in context: A059068 A059069 A084660 this_sequence A087044 A105415 A155920

Adjacent sequences: A002388 A002389 A002390 this_sequence A002392 A002393 A002394

KEYWORD

nonn,cons

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

Fixed my PARI program, had -n Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 19 2009

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 25 13:47 EST 2009. Contains 167481 sequences.


AT&T Labs Research