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A238838
Number of 2n X 2n addition squares in which every digram (s,s;), s' != s, appears once horizontally and once vertically.
1
2, 48, 5760, 5806080, 75246796800, 1780537083494400, 115939740156316876800, 19864514173849162481664000
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OFFSET
1,1
LINKS
Table of n, a(n) for n=1..8.
Gilbert, E. N.,
Latin squares which contain no repeated digrams
, SIAM Rev. 7 1965 189--198. MR0179095 (31 #3346).
FORMULA
a(n) = (2*n)!*
A141599
(n)^2/phi(n).
CROSSREFS
Cf.
A000315
,
A002860
,
A000010
,
A141599
.
Sequence in context:
A087085
A067626
A053071
*
A002820
A196448
A053290
Adjacent sequences:
A238835
A238836
A238837
*
A238839
A238840
A238841
KEYWORD
nonn
,
more
AUTHOR
N. J. A. Sloane
, Mar 15 2014
STATUS
approved
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Last modified August 18 12:24 EDT 2024. Contains 375269 sequences. (Running on oeis4.)