>> From: Carl Devore "devore"
> >> From: "N. J. A. Sloane" "njas"
>
> Is this a known bug?
> > with(numtheory);
> > invphi(1610510);
> []
> > phi(1771561);
> 1610510
> In other words invphi(1610510); gave an incorrect answer.
My investigation so far shows that this bug will occur for
invphi((p-1)*p^n) for n>1 and p any of the primes
11, 23, 29, 31, 47, 53, 59, 67, 71, 79, 83, 89, 103, 107, 113, 131, ....
I can't see the pattern of the primes, except that it appears that if p is
such a prime, then so are all primes of the form (4*n+2)*p+1, n= 0, 1,
.... Tracking down the bug and verifying the above conjecture might lead
to an interesting result. Perhaps it is one of your Integer
Sequences. So the smallest example that I can find for this bug
is invphi(10*11^2).
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(NAG)
