A376010 a(n) is the smallest distance between a pair of equal terms in the sequence s(0) = 1, s(1) = r, and s(k) = s(k-1)^2/(4*s(k-2)) mod p for k>=2, where p = prime(n) (=A000040(n)) and r is a primitive root modulo p.

2, 2, 2, 2, 2, 16, 2, 2, 2, 6, 2, 8, 6, 2, 2, 2, 2, 2, 2, 8, 2, 2, 8, 32, 2, 2, 2, 54, 16, 18, 2, 8, 2, 2, 50, 6, 2, 2, 2, 2, 2, 2, 64, 2, 2, 2, 6, 2, 6, 8, 2, 80, 250, 256, 2, 2, 2, 6, 8, 6, 2, 18, 2, 8, 2, 22, 16, 2, 2, 32, 2, 2, 2, 2, 2, 2, 18, 16, 8, 2, 2, 10, 432, 6, 2, 64, 24, 2, 2, 2, 2, 2, 2, 6, 2, 2, 8, 2, 2, 2, 2, 2, 8, 10, 64, 2, 16, 2, 24, 2, 2, 8, 2, 14, 640, 6

Offset: 2

Author

Max Alekseyev, Sep 05 2024

Keywords

• nonn

Comments

a(n) does not depend on the choice of a primitive root r modulo prime(n).

a(n) = prime(n) - 1 iff prime(n) is in A376008.

a(n) = 2 iff prime(n) is in A216371.

a(n) > 2 iff prime(n) is in A268923.

Crossrefs

Cf. A216371, A268923, A376008.