[r-t] Crambo

[Richard Smith]

Alexander Holroyd wrote:

> > Using nothing but 1sts 3rds & 5ths places I only know of true 60s   as
> > those obtained from  Grandsire (P B P B P B)  its reverse and
> > rotations
> > and from the plain course of Stedman / Carter and their reverses &
> > rotations. As you say that there are in fact lots others, I wonder if
> > you have the time, would you send them to me?
>
> I don't have them, but Richard Smith does!

There are 44 half-extents up to rotation, reflection, etc.:

  http://www.mythic-beasts.com/~richard/doubles/extents/

The only four extents with significant symmetry are Carter,
Stedman, Grandsire and that spliced Grandsire / Double
Grandsire extent (or Grandsire with half-lead calls, however
you want to think of it).

> And he can probably also tell
> us which of them can be successfully "Cramboed Up"...

I was just thinking about that...

RAS