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.

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

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