As a very kind colleague pointed out: There is still a typo: the complete absence of any correction. As this mundane finder (apply S_6*, S_5 respectively) pointed out:

SHOULD READ:

----- O_h = Z[(1 + sqrt(-h))/2] for -h = -3, -7, -11, -19, -43, -67, -163 ----- ((( And NOT:

...

O_h = Z[(1 + sqrt(h))/2] for -h = -3, -7, -11, -19, -43, -67, -163

))) As my maternal grandmother used to say: Oy!!!!!!!!!!!!!!!!!!!!!!! I can say this: The descent into total senility is at least interesting! —Dan ———— * But notice that Out(S_6) is different.

On 11/18/16, Dan Asimov <asimov@msri.org> wrote:

...

Correction:

...

On Nov 18, 2016, at 10:30 AM, Dan Asimov <asimov@msri.org> wrote:

Let O_h be the ring of algebraic integers of ℚ(√-h), Then:

O_1 = Z[i]

O_2 = Z[sqrt(-2)]

O_h = Z[(1 + sqrt(h))/2] for h = -3, -7, -11, -19, -43, -67, -163.

The last line should read:

----- O_h = Z[(1 + sqrt(h))/2] for -h = -3, -7, -11, -19, -43, -67, -163. -----

(and in that e-mail "discover" should be "discoverer". Argggh.