A389572 a(n) is the minimum possible value of max{x_1, x_2, ..., x_n}, where x_1, ..., x_n are distinct positive integers such that x_1^2+1, ..., x_n^2+1 are pairwise coprime.

1, 2, 4, 6, 10, 14, 16, 20, 24, 26, 34, 36, 40, 46, 50, 54, 56, 66, 74, 76, 84, 90, 94, 104

Offset

1,2

Comments

a(25) <= 110. - Sean A. Irvine, Oct 16 2025

Links

Table of n, a(n) for n=1..24.

Example

For n = 4, (x_1, x_2, x_3, x_4) = (1, 2, 4, 6) gives a solution because (x_1^2+1, ..., x_4^2+1) = (2, 5, 17, 37) are pairwise coprime.

Crossrefs

Cf. A008578.

Sequence in context: A075574 A104692 A066755 * A089238 A005574 A109807

Adjacent sequences: A389569 A389570 A389571 * A389573 A389574 A389575

Keyword

nonn,more

Author

Yifan Xie, Oct 08 2025

Extensions

a(21)-a(24) from Sean A. Irvine, Oct 16 2025

Status

approved