A082022 In the following square array a(i,j) = Least Common Multiple of i and j. Sequence contains the product of the terms of the n-th antidiagonal.
1, 4, 18, 576, 1200, 518400, 1587600, 180633600, 1646023680, 13168189440000, 461039040000, 229442532802560000, 86553098311680000, 3753113311877529600, 834966920275488000000
Offset: 1
Keywords
Examples
1 2 3 4 5... 2 2 6 4 10... 3 6 3 12 15... 4 4 12 4 20... 5 10 15 20 5... ... The same array in triangular form is 1 2 2 3 2 3 4 6 6 4 5 4 3 4 5 ... Sequence contains the product of the terms of the n-th row.
Programs
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PARI
for(n=1,20,p=1:for(k=1,n,p=p*lcm(k,n+1-k)):print1(p","))
Formula
Prod(k=1...n, lcm(k, n+1-k)).
Extensions
Corrected and extended by Ralf Stephan, Apr 08 2003
Comments