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A230563 Smallest number that is the sum of three positive n-th powers in more than one way. 1
5, 27, 251, 2673, 1375298099, 160426514 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(7) > 10^26 (if it exists). - Donovan Johnson, Nov 22 2013

From Duncan Moore, Oct 07 2017: (Start)

This sequence is the correct version of A046093.

a(7) > 33055^7 ~ 4.31*10^31 (if it exists). (End)

REFERENCES

G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, section 21.11.

LINKS

Table of n, a(n) for n=1..6.

EXAMPLE

5 = 1^1 + 1^1 + 3^1 = 1^1 + 2^1 + 2^1.

27 = 1^2 + 1^2 + 5^2 = 3^2 + 3^2 + 3^2.

251 = 1^3 + 5^3 + 5^3 = 2^3 + 3^3 + 6^3.

2673 = 2^4 + 4^4 + 7^4 = 3^4 + 6^4 + 6^4.

1375298099 = 3^5 + 54^5 + 62^5 = 24^5 + 28^5 + 67^5.

160426514 = 3^6 + 19^6 + 22^6 = 10^6 + 15^6 + 23^6.

CROSSREFS

Cf. A046093, A230477, A230561, A230562.

Sequence in context: A126119 A105631 A167019 * A204266 A266204 A300621

Adjacent sequences:  A230560 A230561 A230562 * A230564 A230565 A230566

KEYWORD

hard,more,nonn

AUTHOR

Jonathan Sondow, Oct 25 2013

EXTENSIONS

a(4) and a(5) corrected by Donovan Johnson, Oct 28 2013

STATUS

approved

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Last modified December 5 13:26 EST 2019. Contains 329751 sequences. (Running on oeis4.)