A201463 - OEIS

A201463

A list of 25 distinct numbers such that the sum of their reciprocals is 1 and each number is of the form p^i*q^j where p and q are distinct primes.

6, 10, 12, 14, 15, 18, 21, 22, 24, 26, 28, 33, 35, 36, 39, 48, 52, 56, 65, 72, 88, 91, 99, 117, 144

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

At the time Burshtein's paper appeared, this was the smallest example known of this type (it may still be the smallest).

Incidentally, this was the 200000th sequence added to the OEIS.

For the smallest example (20 numbers) of this type, see A237051. - Jon E. Schoenfield, Feb 02 2014

REFERENCES

E. J. Barbeau, Expressing one as a sum of distinct reciprocals: comments and a bibliography, Eureka (Ottawa), 3 (1977), 178-181.

LINKS

N. Burshtein, Improving solutions of Sum_{i=1..k} 1/x_i = 1 ..., Discrete Math., 306 (2006), 1438-1439.

CROSSREFS

KEYWORD

nonn,fini,full

AUTHOR

STATUS

approved