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A027451
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First diagonal of A027447.
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4
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1, 1, 4, 9, 144, 100, 3600, 11025, 78400, 63504, 6350400, 5336100, 768398400, 662547600, 577152576, 2029052025, 519437318400, 463325262400, 150117385017600, 135480939978384
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 21 2009: (Start)
Equals the denominators of MN(z;n)/(n!)^2 for n =>1, see A162990.
(End)
It appears that a(n) = denominator of n^2*sum(1/k^2,k=1..n) [From Gary Detlefs (gdetlefs(AT)aol.com), May 29 2010]
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FORMULA
| Numerators of sequence a[ n, n ] in (a[ i, j ])^3 where a[ i, j ] = 1/i if j<=i, 0 if j>i
Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 21 2009: (Start)
a(n) = (lcm($1..n)/n)^2
(End)
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CROSSREFS
| Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 21 2009: (Start)
Equals A002944(n)^2
Equals A001044(n-1)/A025527(n)^2
(End)
Sequence in context: A063783 A168138 A128524 * A035127 A061267 A061269
Adjacent sequences: A027448 A027449 A027450 * A027452 A027453 A027454
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KEYWORD
| nonn
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AUTHOR
| Olivier Gerard (olivier.gerard(AT)gmail.com)
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