[seqfan] How many ways to dissect a square into 4 congruent pieces

[Neil Sloane]

Continuing to go through the back issues
of Popular Computing, I came across A003213.
Sent to me by Tom Parkin, vice-president at Control Data Corp.

It looks like there has been no progress on this problem since 1973, even
though it
was on the front cover of Vol. 1, No. 7, in 1973, and
is one of the few illustrations in the 1995 EIS.

It's a lovely problem.  I've scanned in some of the associated documents.
See A003213. Many it is time someone found the next term!

Tom Parkin estimates it would take him 5 to 10 minutes to get the next
term, a(6) in A003213, on the CDC STAR machine in 1973
and 30 to 60 hours to get a(7).

As far as I know he never did those runs.

Best regards
Neil

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com