

A201648


The fourth of the five known sets of nine distinct odd numbers the sum of whose reciprocals is 1.


30




OFFSET

1,1


COMMENTS

John Leech showed that nine is the smallest number of odd numbers with this property.
This set was apparently discovered by S. Yamashita in 1976.


REFERENCES

R. K. Guy, Unsolved Problems in Number Theory (UPINT), Section D11.


LINKS

Table of n, a(n) for n=1..9.
Nechemia Burshtein, The equation sum(i=1,9,1/xi)=1 in distinct odd integers has only the five known solutions, Journal of Number Theory, Volume 127, Issue 1, November 2007, Pages 136144.
The Prime Puzzles and Problems Connection, Problem 35
Index entries for sequences related to Egyptian fractions


CROSSREFS

There are five known sets of nine odd numbers with this property: A201644, A201646, A201647, A201648, A201649.
Sequence in context: A260124 A201646 A201647 * A077374 A133848 A220077
Adjacent sequences: A201645 A201646 A201647 * A201649 A201650 A201651


KEYWORD

nonn,fini,full


AUTHOR

N. J. A. Sloane, Dec 03 2011


STATUS

approved



