[seqfan] Re: A018805 optimizations

[M. F. Hasler]

On Thu, Jan 19, 2017 at 9:36 AM, David Wilson <davidwwilson at comcast.net>
wrote:

> For a while I've had an idea for optimizations for A018805(n) = { 1 <= x <=
> n, 1 <= y <= n, gcd(x, y) = 1 }.
> I was able to compute a(n) for powers of 10 up to 10^12 in a few minutes.
> I
> got
> ...

1e12 607927101854119608051819
>

The sequence c(n)/100^n =
(1, .63,
.6087, .608383, .60794971, .6079301507, .607927104783, .60792712854483,
.6079271032731815, .607927102346016827, .60792710185772432731,
.6079271018566772422279, .607927101854119608051819,
...)
seems to converge to
A059956 <https://oeis.org/A059956> Decimal expansion of 6/Pi^2.

Of course, this is maybe just a coincidence (to 11+ digits....?)

Maximilian