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A120076
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Numerators of row sums of rational triangle A120072/A120073.
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3
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3, 37, 169, 4549, 4769, 241481, 989549, 9072541, 1841321, 225467009, 227698469, 38801207261, 39076419341, 196577627041, 790503882349, 229526961468061, 230480866420061, 83512167402400421, 3351610394325821
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OFFSET
| 2,1
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COMMENTS
| The corresponding denominators are given by A120077.
See the W. Lang link under A120072 for more details.
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FORMULA
| a(n)=numerator(r(m)), with the rationals r(m):=sum(A120072(m,n)/A120073(m,n),n=1..m-1),m>=2.
The rationals are r(m)= Zeta(2;m-1) - (m-1)/m^2, m>=2, with the partial sums Zeta(2;n):=sum(1/k^2,k=1..n). See the W. Lang link under A103345.
O.g.f. for the rationals r(m), m>=2: ln(1-x) + polylog(2,x)/(1-x).
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EXAMPLE
| The rationals A120076(m)/A120077(m), m>=2, begin with [3/4, 37/36,
169/144, 4549/3600, 4769/3600,..].
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CROSSREFS
| Sequence in context: A109835 A066364 A106995 * A119938 A196978 A197163
Adjacent sequences: A120073 A120074 A120075 * A120077 A120078 A120079
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KEYWORD
| nonn,easy,frac
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AUTHOR
| Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Jul 20 2006
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