A211128 - OEIS

A211128

One of 17 possible sets of eleven numbers of the form 3^alpha 5^beta 7^gamma whose sum of reciprocals is 1.

3, 5, 7, 9, 15, 21, 25, 27, 49, 1225, 6615

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OFFSET

1,1

REFERENCES

Burshtein, Nechemia. All the solutions of the equation Sum_{i=1..11}} 1/x_i = 1 in distinct integers of the form x_i = 3^alpha 5^beta 7^gamma. Discrete Math. 308 (2008), no. 18, 4286--4292. MR2427761 (2009e:11061)

LINKS

Table of n, a(n) for n=1..11.

CROSSREFS

The 17 solutions are given in A211118-A211134. Cf. A201643, A201644, A201646, A201647, A201648, A201649.

Sequence in context: A211137 A056761 A108347 * A211129 A211127 A211130

Adjacent sequences: A211125 A211126 A211127 * A211129 A211130 A211131

KEYWORD

nonn,fini,full

AUTHOR

N. J. A. Sloane, Apr 02 2012

STATUS

approved