A201650 - OEIS

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A201650

Allan Johnson's set of 48 squarefree numbers whose reciprocals add to 1, with the property that each number has exactly two distinct prime factors.

4

6, 10, 14, 15, 21, 22, 26, 33, 34, 35, 38, 39, 46, 51, 55, 57, 58, 62, 65, 69, 77, 82, 85, 86, 87, 91, 93, 95, 115, 119, 123, 133, 155, 187, 203, 209, 215, 221, 247, 265, 287, 299, 319, 323, 391, 689, 731, 901

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

OFFSET

1,1

REFERENCES

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

LINKS

Table of n, a(n) for n=1..48.

G. L. Honaker, Jr., Prime Curios!: 1

Tatsuru Watanabe, New examples of the representation of 1 by the sum of reciprocals of semiprime numbers, arXiv:2009.03275 [math.NT], 2020. Has more 48-sets and 17 47-sets.

Index entries for sequences related to Egyptian fractions

CROSSREFS

Cf. A201463, A201464, A201514.

Cf. A334342 (for a set of 47 terms).

Sequence in context: A006881 A030229 A334342 * A201514 A201464 A162730

Adjacent sequences: A201647 A201648 A201649 * A201651 A201652 A201653

KEYWORD

nonn,fini,full

AUTHOR

N. J. A. Sloane, Dec 03 2011

STATUS

approved