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A201646 The second of the five known sets of nine distinct odd numbers the sum of whose reciprocals is 1. 28
3, 5, 7, 9, 11, 15, 21, 135, 10395 (list; graph; refs; listen; history; text; internal format)
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.

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: A209492 A118360 A077799 * A201647 A201648 A077374

Adjacent sequences:  A201643 A201644 A201645 * A201647 A201648 A201649

KEYWORD

nonn,fini,full

AUTHOR

N. J. A. Sloane, Dec 03 2011

STATUS

approved

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Last modified November 26 03:41 EST 2014. Contains 250017 sequences.