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A227611 Number of ways to express 2/n as Egyptian fractions in just three terms: 2/n = 1/x + 1/y + 1/z with 0 < x < y < z. 3
0, 1, 5, 6, 9, 15, 14, 22, 21, 30, 22, 45, 17, 36, 72, 62, 22, 69, 29, 84, 77, 56, 39, 142, 48, 53, 82, 124, 30, 178, 34, 118, 94, 67, 176, 191, 29, 74, 151, 274, 37, 227, 37, 145, 220, 87, 57, 342, 80, 146, 138, 162, 39, 216, 214, 322, 134, 100, 73, 461, 31, 84, 316, 257, 197, 304, 47, 199, 166, 435, 69, 508, 34, 79, 317 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

See A073101 for the 4/n conjecture due to Erdős and Straus.

LINKS

Table of n, a(n) for n=1..75.

MATHEMATICA

f[n_] := Length@ Solve[2/n == 1/x + 1/y + 1/z && 0 < x < y < z, {x, y, z}, Integers]; Array[f, 75]

CROSSREFS

Cf. A002966, A073546.

Cf. A227610 (1/n), A075785 (3/n), A073101 (4/n), A075248 (5/n), A227612.

Sequence in context: A301658 A286338 A117951 * A124519 A322959 A154311

Adjacent sequences:  A227608 A227609 A227610 * A227612 A227613 A227614

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Jul 17 2013

STATUS

approved

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Last modified August 18 13:25 EDT 2019. Contains 326100 sequences. (Running on oeis4.)