login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A176914 List of pairs of primes p_i < p_j such that p_i*p_j = p_i + p_{i+1} + p_{i+2} + ... + p_j. 0
2, 5, 3, 13, 5, 31, 7, 53, 3536123, 128541727 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

First four pairs were found by F. Russo and the fifth by Philip Gibbs. It is not known whether other pairs exist.

REFERENCES

A. Murphy, "Smarandache friendly numbers and a few more sequences", Smarandache Notions Journal, Vol. 12, 1-2-3, Spring 2001.

LINKS

Table of n, a(n) for n=1..10.

Philip Gibbs, A Fifth Smarandache Friendly Prime Pair

Felice Russo, On a problem concerning the Smarandache friendly prime pairs

Digital Library of Sciences

EXAMPLE

(2, 5) is a pair because 2 and 5 are primes and 2*5 = 2 + 3 + 5. Similarly (3, 13) is a pair because 3 and 13 are primes and 3*13 = 3 + 5 + 7 + 11 + 13.

CROSSREFS

Sequence in context: A279342 A169852 A318189 * A194010 A229609 A242171

Adjacent sequences:  A176911 A176912 A176913 * A176915 A176916 A176917

KEYWORD

nonn,more

AUTHOR

G. Ornea (gornea2005(AT)gmail.com), Apr 28 2010

EXTENSIONS

Edited by N. J. A. Sloane, Jul 02 2017

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 3 14:34 EDT 2022. Contains 357237 sequences. (Running on oeis4.)