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A198889
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Square array in A071223 read by antidiagonals.
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1
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2, 2, 2, 2, 6, 2, 2, 12, 6, 2, 2, 20, 24, 6, 2, 2, 30, 72, 24, 6, 2, 2, 42, 172, 120, 24, 6, 2, 2, 56, 352, 480, 120, 24, 6, 2, 2, 72, 646, 1512, 720, 120, 24, 6, 2, 2, 90, 1094, 3976, 3600, 720, 120, 24, 6, 2, 2, 110, 1742, 9144, 14184, 5040, 720, 120, 24, 6, 2, 2, 132, 2642, 18990, 45992, 30240, 5040, 720, 120
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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2,1
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REFERENCES
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T. M. Cover, The number of linearly inducible orderings of points in d-space, SIAM J. Applied Math., 15 (1967), 434-439.
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LINKS
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Table of n, a(n) for n=2..76.
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FORMULA
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See A071223, which is the main entry for this array.
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EXAMPLE
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Array begins
2 2 2 2 2 ...
2 6 6 6 6 ...
2 12 24 24 24 ...
2 20 72 120 120 ...
2 30 172 480 720 ...
....
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MAPLE
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A071223 := proc(n, k)
if k=1 and n>=2 then
2
elif n=2 and k>=1 then
2
elif k>=n-1 then
n!
else
procname(n-1, k)+(n-1)*procname(n-1, k-1)
fi ;
end proc:
for d from 3 to 16 do
for k from 1 to d-2 do
n := d-k ;
printf("%d, ", A071223(n, k)) ;
end do:
end do; # R. J. Mathar, Oct 31 2011
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CROSSREFS
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Cf. A071223.
Sequence in context: A073124 A070877 A156717 * A130754 A164126 A163368
Adjacent sequences: A198886 A198887 A198888 * A198890 A198891 A198892
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KEYWORD
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nonn,tabl
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AUTHOR
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N. J. A. Sloane, Oct 30 2011
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STATUS
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approved
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