A377026 Numbers k such that 2^(2^k+1) == -1 (mod k^2).

1, 3, 9, 171, 3249, 97641, 1855179, 29884473, 55753011, 567804987, 892145817, 1059307209

Offset

1,2

Comments

It seems that these are cubefree terms of A006521.

Links

Table of n, a(n) for n=1..12.

Crossrefs

Subsequence of A006521.

Sequence in context: A348141 A217638 A101967 * A078590 A358704 A061963

Adjacent sequences: A377023 A377024 A377025 * A377027 A377028 A377029

Keyword

nonn,more

Author

Thomas Ordowski, Oct 13 2024

Status

approved