login
This site is supported by donations to The OEIS Foundation.

 

Logo

The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, njasloane@gmail.com

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A139520 Denominators of an Egyptian fraction for Catalan constant, using only prime numbers and allowing repetitions. 2
2, 3, 13, 179, 8161, 17319373, 24288185721827, 115965508643355137277722177, 235520782452648150490328050427067627593114827790363, 34927738441197833781363566983541975805101681093066970452740268721673910282017002081858804680098723909 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Good approximation up to 789 decimal digits.

REFERENCES

Mohammad K. Azarian, Sylvester's Sequence and the Infinite Egyptian Fraction Decomposition of 1, Problem 958, College Mathematics Journal, Vol. 42, No. 4, September 2011, p. 330.  Solution published in Vol. 43, No. 4, September 2012, pp. 340-342.

LINKS

Table of n, a(n) for n=0..9.

MAPLE

P:=proc(n) local a, i; a:=evalf(Catalan, 100); for i from 1 by 1 to n do if 1/ithprime(i)<a then a:=a-1/ithprime(i); print(a); print(ithprime(i)); fi; od; end: P(100000);

CROSSREFS

Cf. A139514-A139519, A139521-A139523.

Sequence in context: A113785 A118323 A113494 * A132535 A056806 A270403

Adjacent sequences:  A139517 A139518 A139519 * A139521 A139522 A139523

KEYWORD

easy,nonn,frac

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Apr 28 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified May 27 13:22 EDT 2017. Contains 287205 sequences.