[seqfan] A111076

[Tomasz Ordowski]

Hello SeqFans!

Let a(n) = A111076(n) : https://oeis.org/A111076
If p is an odd prime, then a(p)^{lambda(p)/2} = a(p)^{(p-1)/2} == -1 (mod
p).
Conjecture: If lambda(n) = phi(n), then a(n)^{lambda(n)/2} == -1 (mod n).
   Maybe someone knows how to prove it?
Numbers m such that lambda(m) < phi(m) and a(m)^{lambda(m)/2} == -1 (mod m)
are 28, 33, 42, 57, 65, 76, 93, 99, 124, 126, 129, 138, 145, 171, 172, 177,
185, ...

Best regards,

Thomas