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A295169 a(n) = smallest number k with n prime factors such that (2d)^2 + (k/d)^2 is prime for every d | k. 1
1, 3, 65, 5757 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Such k must be an odd squarefree number.

Conjecture: the sequence is infinite.

a(4) > 10^10 if it exists. - Charles R Greathouse IV, Nov 28 2017

LINKS

Table of n, a(n) for n=0..3.

CROSSREFS

Subsequence of A236423(n+1)/2 for n > 0.

Cf. A295124.

Sequence in context: A012804 A012837 A036778 * A065400 A091470 A028567

Adjacent sequences:  A295166 A295167 A295168 * A295170 A295171 A295172

KEYWORD

nonn,more

AUTHOR

Thomas Ordowski, Nov 16 2017

EXTENSIONS

a(3) from Paolo P. Lava, Nov 16 2017

STATUS

approved

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Last modified January 20 03:32 EST 2019. Contains 319323 sequences. (Running on oeis4.)