semimagic squares: 1, 0, 9, ...
זקיר סעידוב - ד\"ר/Zakir Seidov Ph.D.
zakirs at yosh.ac.il
Fri Aug 8 14:14:07 CEST 2003
Eric, and all SeqFans,
how many are there
3x3 squares modulo rotation/reflection
with 1, 2, 3, ..., 9 distinct digits?
with 1 digit we have n=3 distinct squares (from 9 without modulo rot/ref):
1 . . . 1 . . . .
. . . . . . . 1 .
. . . . . . . . .
====== ===== =====
1-1 1-2 1-3
with 2 digits we have n=12 (from 9*8=72 without modulo rot/ref):
1 2 . 1 . 2 1 . . 1 . . 1 . .
. . . . . . . 2 . . . 2 . . .
. . . . . . . . . . . . . . 2
===== ===== ===== ===== =====
2-1 2-2 2-3 2-4 2-5
. 1 2 . 1 . . 1 . . 1 . . 1 .
. . . . 2 . . . 2 . . . . . .
. . . . . . . . . . 2 . . . 2
===== ===== ===== ===== =====
2-6 2-7 2-8 2-9 2-10
. 2 . . . 2
. 1 . . 1 .
. . . . . .
====== =====
2-11 2-12
also:
with 3 digits we have n=66 (from 72*7=504 without modulo rot/ref)
with 4 digits we have n=378 (from 504*6=3024 without modulo rot/ref)
now, because for 4 digits there are no symmetrical squares,
the next figures are trivial:
with 5 digits we have n=378*5=1890 (from 3024*5=15120 without modulo rot/ref)
with 6 digits we have n=1890*4=7560 (from 15120*4=60480 without modulo rot/ref)
with 7 digits we have n=7560*3=22680 (from 60480*3=181440 without modulo rot/ref)
with 8 digits we have n=22680*2=45360 (from 181440*2=362880 without modulo rot/ref)
with 9 digits we have n=45360*1=45360 (from 9!=362880 without modulo rot/ref)
Are you agree with these figures?
How to generate all these
say 45360 distinct squares (for say 8/9 digits)?
Neil,
are
3,12,66,378,1890,7560,22680,45360,45360
OK for OEIS?
sorry for lengthy post...
zak
%%%%%%%%
-----Original Message-----
From: Eric W. Weisstein [mailto:eww at wolfram.com]
Sent: Thursday, August 07, 2003 2:57 PM
To: Sequence Fans Mailing List
Subject: semimagic squares: 1, 0, 9, ...
There are nine *semimagic* (cf. A006052) squares of order 3 modulo
rotation/reflection:
{{{1, 5, 9}, {6, 7, 2}, {8, 3, 4}},
{{1, 5, 9}, {8, 3, 4}, {6, 7, 2}},
{{1, 6, 8}, {9, 2, 4}, {5, 7, 3}},
{{1, 8, 6}, {9, 4, 2}, {5, 3, 7}},
{{2, 4, 9}, {6, 8, 1}, {7, 3, 5}},
{{2, 6, 7}, {9, 1, 5}, {4, 8, 3}},
{{2, 7, 6}, {9, 5, 1}, {4, 3, 8}},
{{3, 4, 8}, {5, 9, 1}, {7, 2, 6}},
{{3, 7, 5}, {8, 6, 1}, {4, 2, 9}}}
How many are there for higher orders? Any takers?
Cheers,
-E
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