A295169 a(n) = smallest number k with n prime factors such that (2d)^2 + (k/d)^2 is prime for every d | k.

1, 3, 65, 5757

Offset: 0

Author

Thomas Ordowski, Nov 16 2017

Keywords

• nonn
• more

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

Crossrefs

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

Cf. A295124.

Extensions

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