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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
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.
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
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