A075785 Number of ways to express 3/n as Egyptian fractions in just three terms.

0, 1, 1, 3, 7, 6, 6, 16, 15, 15, 13, 22, 8, 27, 30, 26, 21, 45, 8, 59, 36, 29, 20, 62, 32, 45, 69, 67, 27, 84, 14, 59, 56, 44, 129, 142, 15, 45, 53, 130, 31, 124, 21, 131, 178, 40, 29, 118, 38, 88, 67, 102, 43, 191, 102, 180, 74, 57, 43, 274, 21, 75, 227, 86, 144, 145, 23, 121, 87

Offset

1,4

Links

Table of n, a(n) for n=1..69.

Christian Elsholtz, Sums Of k Unit Fractions

David Eppstein, Algorithms for Egyptian Fractions

Mathematica

Needs["MyOwn`Egypt`"]; Table[ Length[ EgyptianFraction[3/n, Method -> Lexicographic, MaxTerms -> 3, MinTerms -> 3, Duplicates -> Disallow, OutputFormat -> Plain]], {n, 5, 70}]
f[n_] := Length@ Solve[3/n == 1/x + 1/y + 1/z && 0 < x < y < z, {x, y, z}, Integers]; Array[f, 69] (* Robert G. Wilson v, Jul 17 2013 *)

Crossrefs

Cf. A073101, A347566, A347569.

Sequence in context: A338065 A278818 A245259 * A105735 A213610 A296343

Adjacent sequences: A075782 A075783 A075784 * A075786 A075787 A075788

Keyword

nonn

Author

Robert G. Wilson v, Aug 18 2002

Status

approved