1,6

This sequence coincides with A216321 for all n values from A206551 (cyclic multiplicative Modd n group) and the entry is 0 otherwise (if no primitive root exists, that is, n is from the complementary sequence A206552).

Table of n, a(n) for n=1..85.

a(n) = A216321(n) if n belongs to the sequence A206551 and a(n)=0 if n belongs to A206552.

a(8) = phi(phi(2*8)/2) = 2 , with phi = A000010, because 8 = A206551(8).

a(12) = 0 because 12 = A206552(1).

Cf. A216321, A046144 (modulo n analog).

Sequence in context: A078228 A119762 A153667 * A335383 A125914 A086668

Adjacent sequences: A216319 A216320 A216321 * A216323 A216324 A216325

nonn

Wolfdieter Lang, Sep 21 2012

approved