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A282578 Least k such that k^n is the sum of two distinct proper prime powers (A246547), or 0 if no such k exists. 0
12, 5, 5, 3, 62 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Corresponding values of k^n are 12, 25, 125, 81, 916132832, ...

LINKS

Table of n, a(n) for n=1..5.

Wikipedia, Beal's conjecture

FORMULA

a(p) <= 2 * (2^p - 1) where p is in A000043 since (2^p - 1)^p + (2^p - 1)^(p + 1) = (2 * (2^p - 1))^p.

EXAMPLE

a(1) = 12 because 12 = 2^2 + 2^3.

a(2) = 5 because 5^2 = 2^4 + 3^2.

a(3) = 5 because 5^3 = 2^2 + 11^2.

a(4) = 3 because 3^4 = 2^5 + 7^2.

a(5) = 62 because 62^5 = 31^5 + 31^6.

a(9) = 2 because 2^9 = 7^3 + 13^2.

CROSSREFS

Cf. A001597, A225102, A246547, A282550.

Sequence in context: A157782 A002679 A133208 * A205141 A122561 A110185

Adjacent sequences:  A282575 A282576 A282577 * A282579 A282580 A282581

KEYWORD

nonn,more

AUTHOR

Altug Alkan, Feb 20 2017

STATUS

approved

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Last modified January 27 12:01 EST 2020. Contains 331295 sequences. (Running on oeis4.)