A387107 a(n) = psi(2^n-1), where psi = A002322.

1, 2, 6, 4, 30, 6, 126, 16, 72, 30, 88, 12, 8190, 126, 150, 256, 131070, 72, 524286, 120, 1008, 2728, 178480, 240, 1800, 8190, 262656, 1008, 39672, 1650, 2147483646, 65536, 2397912, 131070, 1106280, 216, 616318176, 524286, 12743640, 61680, 26815350376, 43344, 1186422030

Offset: 1

Author

Emanuele Pace, Aug 16 2025

Keywords

• nonn

Crossrefs

Cf. A002322, A000225.

Programs

Mathematica

a[n_] := CarmichaelLambda[2^n - 1]; Array[a, 50] (* Amiram Eldar, Aug 16 2025 *)

PARI

a(n) = lcm(znstar(2^n-1)[2]); \\ Michel Marcus, Aug 22 2025

Formula

a(n) = A002322(A000225(n)).