[seqfan] Re: Two-fold symmetry sequence

[N. J. A. Sloane]

I've added the Schneider sequence (it is now A144554 and needs more terms)

I've also added the missing columns from the Redelmeier table
(thanks to Joseph Myers for pointing out their omission - and
for clarifying the definitions of the columns in that table!)

I've also added the precise definitions of the symm. groups
involved to all of the 8 or 9 sequences arising from the table
(I hope my versions of the definitions are correct - these 
little groups are easy to confuse with each other)

Neil